The Problem of Atheism and Zetetics

Before examining the epistemological arguments, we must name the method of discussion of militant zetetics. Lavagna sums it up in two points from the very opening of his book:

"The argumentative method of many zeteticians toward theists comes down to two points: (1) psychoanalyze the believer, presupposing that he believes in God because of an unconscious need for comfort, for existential consolation; (2) caricature the theist arguments in order to refute them more easily — in short, 'attacking straw men.'" — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 17^[7]

The Caricature of Christianity

The method appears in its pure state in the definition Durand copies from the mythicist Richard Carrier:

"Christianity: the belief that a cosmic Jewish zombie can make you live forever if you symbolically eat his flesh and telepathically promise to accept him as your master; thus he can remove an evil force present in your soul ever since a woman made from a rib let herself be convinced by a talking serpent to eat the fruit of a magic tree. […] A Christian is indeed someone who believes in a scenario of this nature." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 348-349^[8]

This definition is not an analysis: it is mockery. No Christian theologian has ever formulated the faith in these terms. It is what analytic philosophy calls a straw-man argument: you replace your opponent's position with a caricature, you refute the caricature, and you believe you have refuted your opponent's position. The criticism here targets theses and procedures — caricature, mockery, imputing motives —, not persons: we judge neither the supposed dispositions nor the culture of the authors; we refute their arguments with evidence, in accordance with charity and with the Ignatian rule that asks us to save our neighbor's proposition first rather than condemn it^[9].

The Genetic Fallacy: Judging a Belief by Its Origin

The psychoanalytic procedure consists in judging a belief not on its content but on its supposed origin (psychological, sociological, cultural). This is what classical logic calls the genetic fallacy. Typical examples in Durand:

"One can believe in God for many reasons: out of tradition, out of emotion, in response to existential anguish, out of sensitivity to a certain aesthetics of the universe, to give meaning to life, out of a sense of a poetry at work in the cosmos…, but these motivations do not rest on rational proofs of God's existence." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 262^[10]

The argument never touches the question under debate. Whether one believes in God for good or bad reasons says nothing about God's existence. Lavagna replies:

"It is not because someone believes in God for bad reasons that God does not exist. The truth or falsity of a belief in no way depends on the origin of the belief in question." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 18^[11]

The Symmetrical Reversal

The sophistical character of the procedure appears immediately upon reversal. One can say to Durand, word for word:

"One can be an atheist for many reasons: out of tradition, out of emotion, in response to an existential rebellion against God's authority, or quite simply out of a refusal to face the reality of one's sin; but these motivations do not rest on rational proofs of God's nonexistence." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 18^[12]

The argument reverses perfectly. Neither version is a genuine argument about God's existence or nonexistence: they are psychological analyses with no place in a metaphysical demonstration. "Sterile ping-pong," concludes Lavagna^[13].

Comforting Reassurance Proves Nothing

Durand also argues from the "comforting" character of faith:

"What is the rhetoric of monotheism? It consists in positing the existence of an all-powerful God who loves the (true) believer, who watches over him, who wants his good and who will reward him. […] It is the most comforting, the most consoling idea that could possibly be. Religion fits the human mind like a glove — our biases, our expectations, our motivations, anxieties, and aspirations." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 47-48^[14]

The argument silently assumes that the comfort brought by a belief would prove its falsity. But exactly the reverse can be true: one may well refuse a truth because it disturbs us. "The fact that an idea is comforting or consoling does not imply that it is false," replies Lavagna^[15]. And — the decisive argument — "if God exists, then it is not at all improbable that he created human beings with this desire to know him. There is nothing implausible in the fact that God 'shaped' us to fulfill our deepest aspirations"^[16]. That is precisely what Augustine formulated in the fourth century:

"You have made us for yourself, O Lord, and our heart is restless until it rests in you." — Saint Augustine, Confessions, Book I, ch. 1, § 1^[17]

Nor is Christianity particularly "comfortable": it calls us to carry our cross, to forgive our enemies, to renounce ourselves, to fear the particular judgment, to accept suffering as redemptive. That is not the profile of an illusion designed to reassure^[18].

A large share of atheist-theist discussions fail at the door because people do not agree on words. Three confusions are systematically maintained in militant zetetic literature: confusion between classical atheism and mere non-belief, confusion between epistemic and epistemological agnosticism, and confusion between zetetics-as-method and zetetics-as-metaphysics.

Classical Atheism: An Affirmation, Not an Absence

In the philosophy of religion, the received definition since antiquity is crystal clear. Theism is the position that God exists; atheism is the position that God does not exist. Both are positive affirmations about reality, hence two propositions that can be true or false, defended or refuted^[19].

This definition is not a trap set by theists. It is the standard definition among leading atheist philosophers. The philosopher Graham Oppy (Monash University), regarded as one of the world leaders of contemporary philosophical atheism, states it without ambiguity:

"Atheism is the belief that there is no God." — Graham Oppy, Arguing About Gods, Cambridge University Press, 2006, ch. 1^[20]

Paul Draper, atheist philosopher at Purdue University and author of the reference article Atheism and Agnosticism in the Stanford Encyclopedia of Philosophy, writes exactly the same thing, in a neutral academic reference work:

"In philosophy, and more specifically in the philosophy of religion, the term 'atheism' is standardly used to refer to the proposition that God does not exist. Thus, to be an atheist on this definition, it does not suffice to suspend judgment on whether there is a God. It is necessary to deny that there is a God." — Paul Draper, Atheism and Agnosticism, Stanford Encyclopedia of Philosophy^[21]

Robin Le Poidevin, British atheist philosopher, concurs: "An atheist is one who denies the existence of a personal, transcendent creator of the universe, rather than one who simply lives his life without reference to such a being."^[22] John L. Schellenberg, also an atheist, writes that the atheist is not merely someone who "doesn't accept theism" but someone who "opposes it, who affirms that there is no God"^[23]. William L. Rowe, an atheist, writes in the Concise Routledge Encyclopedia of Philosophy: "Atheism is the position that affirms the non-existence of God. It proposes a positive unbelief rather than a mere suspension of belief."^[24]

The Militant Redefinition of the New Atheism

Since the 2000s, and particularly in the wake of the Anglo-Saxon New Atheism (Richard Dawkins, Sam Harris, Christopher Hitchens, Daniel Dennett), a militant redefinition has taken hold. Atheism is presented there as a mere absence of belief in God — on the same footing as not believing in unicorns or the Flying Spaghetti Monster. In France, this redefinition is carried by figures of militant zetetics, notably Durand:

"One can perfectly well be an atheist without any positive belief in God's nonexistence." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 24^[25]

The stakes of this redefinition are not innocent. Lavagna exposes them in a footnote:

"The reason that drives Thomas Durand to give this definition is that it allows him not to have to justify or argue in favor of God's nonexistence, and to impose atheism as a default presupposition." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 47, note 38^[26]

Why This Redefinition Is Philosophically Untenable

The decisive argument is one of pure logic. If atheism were reduced to an absence of belief in God, then:

• plants, pebbles, atoms would all be atheists, since they are without belief in God; there would then be more than 10⁸⁰ atheists in the universe, which makes no sense;
• babies, people in comas, people with profound mental disabilities would be atheists, since they hold no positive belief in God;
• a serious car accident could turn a theist into an atheist by making him lose his memory;
• an agnostic who rates the probability that God exists at 50% would be an atheist — though he has precisely not decided;
• a believer who bets on God in Pascal's manner, prays every day and goes to Mass, but remains intellectually hesitant about the probability of His existence, would be an atheist on this definition^[27].

The other decisive reason is philosophical symmetry. If theism is the affirmation that God exists, then atheism must be, by symmetry, the affirmation that God does not exist. Every -ism in philosophy is a stance taken, not an empty mental state. Marxism, liberalism, materialism, idealism — all designate a thesis defended, not an empty mental state^[28].

A major practical consequence: if atheism were a mere absence of belief, there could be no argument against it. Lavagna says it forcefully:

"If atheism is defined as 'the mental state of absence of belief in God,' then there can in principle be no argument against atheism, for arguments can only attack affirmations about reality. […] An argument for the proposition 'God exists' would no longer be an argument against atheism, which makes no sense." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 50^[29]

Epistemic vs Epistemological Agnosticism

There is, however, a perfectly well-defined term for one who affirms neither that God exists nor that He does not exist: the agnostic. Philosophy distinguishes two variants:

The rational attitude of someone who does not know is epistemic agnosticism, not the negative atheism that people try to pass off as neutral^[30]. "The epistemic agnostic holds that the proposition God exists has roughly as much chance of being true as the proposition God does not exist," Lavagna specifies^[31].

The Terminological Balance Sheet

Lavagna sums up his glossary in three lines:

1. A theist is someone who affirms the proposition "God exists".
2. An atheist is someone who affirms the proposition "God does not exist".
3. An agnostic is someone who affirms the proposition "I do not know whether God exists"^[32].

It is this taxonomy, shared by the reference philosophical dictionaries, that this article retains.

Zetetics: Etymology, History, Ambivalence

The word zetetics comes from the Greek ζητητικός (zêtêtikos), "apt to seek," and ζητεῖν (zêtein), "to seek, to inquire." It denotes first, in Greek antiquity, the attitude of the Pyrrhonian skeptics — Pyrrho of Elis, Sextus Empiricus — who claimed a perpetual inquiry rather than a definitive adherence to a dogma^[33].

The word was taken up again in the modern era, then given its French form in the 1990s by the physicist Henri Broch, professor at the University of Nice-Sophia Antipolis, who defines zetetics as "the art of doubt" and who created the Laboratory of Zetetics (1998). The Observatoire zététique, created in 2003 in Grenoble, popularized this approach by explicitly equating it with "critical thinking" and "methodological skepticism"^[34].

Three remarks are in order here:

1. Zetetics is not a unified philosophical school. It brings together militant atheists (Thomas Durand, Henri Broch on certain points), skeptics in good faith, cognitive-science researchers (Richard Monvoisin), and merely curious citizens. Not all of these people draw the same metaphysical conclusions.
2. Zetetics-as-method — the tools of critical thinking, source verification, identification of cognitive biases — is compatible with any metaphysics (Catholic included).
3. Zetetics-as-metaphysics — the implicit idea that whatever is not measurable does not exist — is by contrast a precise philosophical thesis (scientism + naturalism), which must be rationally defended and which is not self-evident.

It is the latter that poses the problem, and it is the latter that this article aims to deconstruct.

One confusion feeds a good part of the atheist-theist debate: the idea that there is only one valid type of proof — experimental proof, reproducible in a laboratory — and that everything else (history, testimony, philosophy, metaphysics) is a matter of opinion. This confusion is not peculiar to militant zetetics; it is found, with the front reversed, in certain apologists too hasty to make science a tribunal that would prove God the way one proves a theorem. Bolloré and Bonnassies, in Dieu, la science, les preuves, open their work with a precious methodological warning, largely ignored by the rest of their own demonstration.

Five Regimes of Proof, Five Levels of Demand

A mathematical demonstration concerns fully defined abstract objects; its certainty is absolute, once the axioms are accepted. But as soon as we leave this terrain for the real world, the nature of proof changes status:

"In the real domain, by contrast, sound reasoning applied to sound data does not necessarily lead to an exact conclusion […] one would have to apply sound reasoning to the totality of the data or parameters involved in the problem. But in the real world, reality is never entirely known to us." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 40^[35]

"Not absolute" does not mean arbitrary: science reaches extremely high degrees of confidence. But a single missing datum can suffice to invert a conclusion that was logically well constructed:

"As we see in this tragic story, a single missing piece of information, hence not taken into account in the reasoning, led to a result exactly opposite to the one the initial reasoning had reached." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 42^[36]

A scientific model gains authority when it successfully predicts facts that were not expected:

"If the model corresponds to reality, the level of proof is greatly reinforced, especially if the model predicts unexpected consequences that subsequently prove exact." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 42-43^[37]

A refuted model is not necessarily a total error, but an approximation superseded by a more encompassing model:

"Subsequently, Newton's theory of gravitation was replaced by Einstein's theory of Relativity, but that does not mean Newton's theory was false. We simply moved from a good approximation of reality to a more elaborate theory, giving a vision and an approximation still closer to reality." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 44^[38]

Finally, human testimony — which radical methodological doubt would disqualify on principle (see below) — has a variable force according to controllable criteria, neither nil by default nor automatically admissible:

"We see, then, that the value of proof drawn from testimony is exceedingly variable depending on the number and quality of the witnesses. According to the case, the value of proof resulting from testimony can range from nil to very strong." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 50^[39]

The Cosmic Microwave Background: A Risky Prediction That Paid Off

The most instructive example of a well-constructed scientific proof remains the discovery, in 1964, of the fossil radiation predicted by hot Big Bang theory. Arno Penzias and Robert Wilson, two radio astronomers at Bell Laboratories, were trying to eliminate a parasitic background noise in their antenna — they knew nothing of the corresponding cosmological prediction:

"Penzias and Wilson, without the slightest idea and without having sought it, had in fact just discovered the residual presence of the electromagnetic signal emitted at the Big Bang." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 91-92^[40]

The case is pedagogically complete: an earlier theoretical prediction (Gamow, Alpher, Herman), an independent detection by researchers who were not looking for it, the methodical elimination of possible instrumental causes, then the convergence of several teams. It is a far better example of scientific method than the general declarations about "Science" with which militant zetetics contents itself — and a reminder that the standard Big Bang model, today solidly corroborated, became so precisely through this type of confirmed risky prediction^[41].

To discuss honestly, we must acknowledge what is right in the critical approach. Refusing this kernel of truth would commit the inverse of the scientistic error: stopping our ears to a valid argument on the pretext that it comes from the opposing camp. Serious Catholic apologetics never proceeds that way.

The Legitimate Critical Spirit

Zetetics rightly teaches us to:

• verify the sources of an extraordinary claim before adhering to it;
• identify cognitive biases (confirmation bias, post hoc ergo propter hoc, availability bias, Forer/Barnum effect);
• spot fallacies (ad hominem, straw man, false dilemma, appeal to nature, illegitimate appeal to authority);
• demand sound experimental protocols for testable claims (alternative medicines, telepathy, divination, clairvoyance).

On all these points, the authentic Catholic attitude converges with the zetetic attitude. Superstition, naive credulity, charlatans, pseudo-mediums, false prophets, fraudulent healers, sects: all of this is combated by the Church itself, and has been for a long time^[42].

The Church Has Practiced Critical Discernment for Centuries

Far from yielding to credulity, the Catholic Church invented some of the most rigorous discernment procedures in the world. A few examples:

• The Bureau Médical de Lourdes, founded in 1883, examines every declared cure with a rigor for which Saint Pius X requested systematic scientific examination in 1905. Medical examination is assessed against the seven classical criteria known as Lambertini's (Benedict XIV, De Servorum Dei Beatificatione, 1734-1738): a serious illness difficult to cure, an illness not arrived at its final stage, ineffectiveness of medicines, sudden and instantaneous cure, perfect cure, without notable evacuation or prior crisis, without relapse^[43].
• The Comité Médical International de Lourdes (CMIL), created in 1947 as a national committee and turned international in 1954, brings together some twenty physicians of all specialties and forwards a file to the bishop only if they judge the cure certain, lasting, and medically inexplicable^[44].
• In a canonization cause, the historic function of the Promotor Fidei ("devil's advocate") consisted precisely in defending the skeptical position and seeking every reason to doubt the file — a function attached to the Congregation of Rites, instituted in January 1588 in Sixtus V's reorganization of the Curia (constitution Immensa Aeterni Dei, which created the Roman congregations and entrusted the causes of saints to that of Rites). Since John Paul II's reform (constitution Divinus Perfectionis Magister, 25 January 1983), the adversarial trial in contradictory form has disappeared: the Promotor Fidei no longer holds the role of systematic opponent there^[45].
• The diocesan commissions of inquiry on apparitions apply the Norms for Proceeding in the Discernment of Alleged Supernatural Phenomena of the Dicastery for the Doctrine of the Faith (17 May 2024, in force 19 May 2024, Solemnity of Pentecost), which replace the 1978 norms. The Church no longer normally declares the supernatural character of a phenomenon: the ordinary favorable outcome is a nihil obstat ("nothing stands in the way": without expressing certainty about supernatural authenticity, many signs of the Holy Spirit's action are recognized), and six conclusions are possible: nihil obstat ("nothing stands in the way"), prae oculis habeatur ("to be kept before one's eyes": positive signs exist, but confusion or risks require careful discernment and dialogue from the bishop), curatur ("let it be taken care of": without encouraging the already widespread phenomenon, the bishop redirects its spiritual and pastoral aspects), sub mandato ("under mandate": pastoral direction of the place is entrusted to the diocesan bishop), prohibetur et obstruatur ("forbidden and to be prevented": adherence to the phenomenon is not permitted), declaratio de non supernaturalitate ("declaration of non-supernaturality": the Church rules that the phenomenon is not supernatural)^[46]. For every file examined since 2024, only a dated decision — normally a nihil obstat — is authoritative; failing that, the Church has not ruled.

See The Miracles of Lourdes and Discerning Supernatural Phenomena.

Good Skepticism and Bad Skepticism

The decisive distinction, set out by Lavagna, separates two types of skepticism:

"There is a good skepticism and a bad skepticism. Good skepticism forbids itself to believe everything on parole and seeks good reasons to believe within the limits of reason. Bad skepticism, by contrast, doubts absolutely everything. It rejects all forms of certainty in general." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 25^[47]

When an Ideology Dictates Its Conclusions in Advance

The history of twentieth-century science offers a warning that zetetics should take seriously: a doctrine can decide in advance which scientific conclusions are admissible, then persecute those who obtain the wrong result. That is exactly the danger that the authentic critical approach claims to combat — and yet it is what any metaphysical dogmatism applied to science structurally produces.

In the Soviet Union, official dialectical materialism demanded an eternal universe without beginning; several physicists sympathetic to an expanding-universe model paid the professional or personal price for it, in the broader climate of the Stalinist purges^[48]. In Nazi Germany, the campaign of Philipp Lenard and Johannes Stark against "Jewish physics" — including Einstein's relativity — led to the exclusion of scholars such as Max Born, James Franck, and Lise Meitner, and to the destruction of the Göttingen school of mathematics^[49]. At a banquet around 1934, the Nazi Minister of Education Bernhard Rust asked the mathematician David Hilbert how mathematics was faring at Göttingen "now that it is freed from Jewish influence"; Hilbert replied coldly:

"Mathematics at Göttingen? There is really none any more." — David Hilbert, remark reported by his biographer Constance Reid, quoted second-hand by M.-Y. Bolloré and O. Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 156^[50]

These two episodes must be read with historical prudence: racial antisemitism and institutional regimentation are the central causes of the Nazi persecution of scholars, not a mere cosmological dispute, and the Stalinist trials belong to a political context broader than the mere rejection of the Big Bang. But the principle they illustrate remains valid and directly transposable to the question occupying this article: a community that decides in advance, in the name of a metaphysics, which conclusions are admissible no longer exercises the scientific method — it subordinates it. That is precisely what zetetics-as-metaphysics does with scientism when it excludes a priori any conclusion that would fall outside the materialist framework, before even examining the file.

Christianity and science share good skepticism. Zetetics-as-method shares good skepticism. Zetetics-as-metaphysics, by contrast, slides toward bad skepticism, which cannot hold as a complete epistemology, as we shall now show.

Four structural problems undermine militant zetetician epistemology: radical methodical doubt (which undermines itself), scientism (self-refuting), the denial of absolute truth (contradictory), and systematic distrust of human testimony (unworkable).

Radical Methodical Doubt: "One Must Doubt Everything"

Militant zetetics' epistemology defines itself as the art of doubting everything. Durand writes it explicitly:

"I advocate the skeptical approach, which warns us that it is presumptuous and reckless to accept believing what is not supported by good arguments." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 14^[51]

And further on, in the radical version:

"From a certain extremely skeptical point of view, one can consider that it is not possible to prove that the world really exists. One can imagine that the universe is nothing but a fictional backdrop, a sort of matrix. One can imagine that nothing exists, that the universe is mental…" — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 347^[52]

The practical rule he draws from it — "To reach a relative certainty of the truth of X, one must begin by doubting X"^[53] — has something seductive about it; one would think it borrowed from Descartes. But literally applied, it is indefensible.

Must we really begin by doubting that 1 + 1 = 2 before being certain of it? The principle of non-contradiction? Our parents' love for us? The existence of the external world? The fact that it is immoral to torture an infant for pleasure? All doubt begins with a minimal certainty: the reliability of logic, memory, language. One cannot doubt everything, because one cannot doubt with nothing.

"From the moment one doubts everything, there is no longer any way to live normally and to build a solid body of thought, for its foundation can always be called into question. To escape this impasse, one must therefore necessarily admit that at the basis of knowledge there are evidences given by the natural light of reason." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 21^[54]

Total Skepticism Destroys Itself

The objection has been known since antiquity. If one affirms "one must doubt everything," then one must also doubt that very affirmation. But then it loses its authority. Total skepticism is, logically, a performatively contradictory thesis: it undermines itself.

Saint Augustine, who had been a skeptical Manichean for nine years, formulates the classical refutation:

"If I am mistaken, I exist." — Saint Augustine, The City of God, Book XI, ch. 26^[55]

The mere fact of doubting presupposes a subject who doubts, and a subject who doubts exists — so there is at least one certain thing, the existence of the thinking subject. Descartes would take up this idea 1,200 years later.

The Hidden Scientism: "Only Science"

Durand does not hide his scientistic presupposition:

"The scientific method is the only approach available to us for producing objective knowledge, that is, knowledge that remains true whatever the culture, era, mood, or ideology of the individual. […] Scientific theories are therefore the nec plus ultra of objective knowledge." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 38-39^[56]

The objection has been known since the Vienna Circle of the 1920s (Moritz Schlick, Otto Neurath, Rudolf Carnap, A. J. Ayer). Logical positivism held, on the model of the verification principle, that a statement is meaningful only if it is verifiable by experience. In simple words: according to this rule, a sentence would mean something only if one could say which experience would verify it. This principle enjoyed considerable success into the 1950s, before being refuted by the philosophers of science themselves (Karl Popper, Willard Van Orman Quine, Hilary Putnam, Thomas Kuhn)^[57].

The reason for this failure is simple: the verification principle is itself unverifiable. Lavagna writes it plainly:

"The claim 'the scientific method is the only approach available to us for producing objective knowledge' is an affirmation of a… philosophical type! No scientific method will ever be able to verify this claim. Consequently, Thomas Durand's assertion is self-refuted. It logically implies its own falsity." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 22^[58]

All the Domains Excluded by Scientism

If the scientistic thesis is taken seriously, one must reject as non-objective the following:

Lavagna sums up:

"Thomas Durand's verificationist thesis ends up excluding all conceptual truths — logical, mathematical, moral, and philosophical — since these could not be 'tested.' Such an epistemology leads inevitably to a genuine suicide of reason." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 30^[59]

Karl Popper and Falsifiability: A Misunderstood Criterion

Karl Popper proposed in 1934 the criterion of falsifiability as the line of demarcation between science and non-science: a scientific theory must be able to conflict with a possible observation^[60]. In simple words: a theory is scientific only if one can say in advance which imaginable observation would contradict it — if nothing could ever prove it wrong, it is not science. This intuition is precious: it distinguishes Einstein's physics (which could be refuted by eclipse observations) from certain pseudo-sciences (which can always reinterpret awkward facts). But Popper never held that whatever is not experimentally falsifiable is false or irrational:

"I thus felt that if a theory is found to be nonscientific, or 'metaphysical' (as we might say), it is not thereby found to be unimportant, or insignificant, or 'meaningless,' or 'nonsensical.'" — Karl Popper, "Science as Falsification", 1953 lecture published in Conjectures and Refutations, Routledge, 1963^[61]

Popper thus distinguished empirical science from other modes of rational knowledge: a non-refutable theory is not meaningless; it simply cannot claim empirical confirmation in the scientific sense. That is precisely what militant zetetics refuses to hear.

The Denial of Absolute Truth

Durand then moves to an even more radical thesis:

"It is prudent never to claim to possess absolute truth on any subject whatsoever." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 58^[62]

The objection must be taken at its word: Durand does not deny here that absolute truths exist; he judges it imprudent to claim to possess any — an epistemic restriction, not an ontological negation. But erected into a universal rule ("on any subject whatsoever"), this prudence turns against itself: either it claims to be absolutely true, and it excludes itself; or it is only methodological advice, and it forbids nothing. Moreover, we do possess, without imprudence, absolute truths: mathematical theorems, the laws of logic (the principle of non-contradiction — a thing cannot be both true and false at the same time —, the law of contraposition — if "A implies B" is true, then "not-B implies not-A" is true as well), metaphysical truths ("I exist," "something exists"), moral truths ("torturing an infant for pleasure is immoral"). Lavagna gives a reasoned list of them by type^[63].

Systematic Distrust of Human Testimony

The great majority of our everyday knowledge rests on human testimony: date of birth, theorems we cannot demonstrate ourselves, historical facts, medical diagnoses, architectural plans, train timetables, the reliability of the instructor's parachute. Without trust in others' testimony, ordinary life becomes impossible^[64].

The contemporary epistemology of testimony (Coady, Lackey, Audi, Plantinga, Swinburne) recognizes a default principle of credibility: unless we have specific reasons to doubt, we must grant a reasonable degree of trust to others' testimony. That is how we know that Napoleon existed, that Paul of Tarsus was converted, that the Council of Nicaea took place in 325, that the Earth revolves around the Sun^[65].

Aimé Michel clarifies the stakes for non-reproducible phenomena: if such phenomena exist, excluding every fact known by testimony alone would prevent us from discovering them — "we would never be warned of our error." On this hypothesis, their observable effects can be the object of scientific studies, while knowledge of the event itself remains dependent on witnesses. Michel adds that his argument also holds for phenomena that are not yet reproducible. He calls for competent witnesses of opposing opinions: his reasoning justifies inquiry, without by itself establishing the authenticity of any particular miracle^[66].

"If the extremist skepticism of zetetics were applied, one would always have to begin by doubting testimony given on principle, unless you have proof that it is reliable. That would lead to the collapse of nearly all our knowledge, to the point of making life simply impossible to live, so central is trust to our everyday knowledge." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 27^[67]

If atheism is the affirmation that God does not exist, then it carries a burden of proof. It is a principle of elementary epistemology, valid in every discipline: the burden of proof lies with whoever affirms something^[68]. That holds in court, in science, in metaphysics, in theology.

"I Don't Have to Prove My Atheism": A Rhetorical Strategy

The militant zetetician strategy consists precisely in evading this burden. By redefining atheism as an absence of belief, the atheist presents himself as the neutral observer who "awaits proof," while the theist would be the clumsy affirmer who "must prove his case." It is a rhetorically skillful presentation, but an undue reversal of the burden of proof. Durand's peremptory tone is revealing:

"It is rational to admit that science proceeds to bring truth to light; it is unintelligent, that is, literally stupid, to oppose this idea." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022^[69]

This virulence — "unintelligent, literally stupid" — masks an argumentative weakness: brought together with the thesis of p. 38-39 ("the only approach […] for producing objective knowledge"), it amounts to affirming that only science brings truth to light — precisely the massive philosophical thesis that does not demonstrate itself (see above, § The Hidden Scientism).

The Burden of Proof Is Symmetrical

In logic, the principle is simple. When A affirms X and B denies X, both carry a burden of proof as soon as they defend a positive position^[70]:

• "God exists" → present arguments for this affirmation;
• "God does not exist" → likewise present arguments for this affirmation;
• "I do not know" → legitimate exemption; that is the authentic agnostic position.

The theist accepts his burden: he proposes the cosmological argument, the argument from contingency, the fine-tuning of the universe, the moral argument, the argument from consciousness, the historical argument of the Resurrection — see The Proofs of God's Existence — Synthesis, Cosmological Fine-Tuning, The Contingency Argument. The fervent atheist, for his part, does not accept his. That is the source of a large share of the misunderstandings.

The Bogus "Alicornism" Argument

A classic zetetician rhetoric consists in comparing God to unicorns:

"It is generally readily admitted that a non-specialist in unicorns or extraterrestrial visits is perfectly legitimate to assess the question of their existence, provided he takes care to ascertain the definition of the phenomenon before judging it." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 25^[71]

Durand even pushes the comparison as far as the Flying Spaghetti Monster:

"Pastafarianism tells that the universe was created by the Flying Spaghetti Monster after an overly boozy evening. […] One can even defend the idea that Pastafarianism has an advantage over other religions: it holds that its God has a sense of humor, which brings him closer to perfection." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 59-60^[72]

The argument is fragile for three reasons. First, it devalues the concept of God by caricature: God, in classical theism, is not a finite object among the objects of the world, but the uncaused transcendent cause of all being. There is strictly no parallel with unicorns or teapots in orbit. Second, it treats on equal footing a concept seriously defended by no one (unicorns) and a concept defended for 2,500 years by the greatest philosophers: Plato, Aristotle, Plotinus, Augustine, Anselm, Thomas Aquinas, Descartes, Leibniz, Pascal, Kierkegaard, Newman, Plantinga, Swinburne, Craig, van Inwagen. Third, it places on the atheist a burden of proof he refuses to accept: when one positively affirms "God does not exist," one must give reasons — otherwise one is in gratuitous belief.

"Are We All Atheists?": The Bachelor Analogy

A popular variant among zeteticians, taken up by Durand:

"Among the tens of thousands of divinities worshipped through history, monotheists are separated from atheists by a single last god. Many monotheists would consider it absurd to be called 'atheists.' Likewise, one who does not believe in the existence of unicorns would not appreciate being labeled an 'alicornist' or 'amonokerist.'" — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 228-229^[73]

The objection is appealing, but weakly built. Lavagna replies with a limpid analogy:

"It would be as if a bachelor said to a married man: 'You too are single with respect to all other women. I am just single with respect to one woman more.' That makes no sense. Either one is single, or one is not. Likewise, either one is an atheist, or one is not." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 54^[74]

There is furthermore a major ontological difference between the God of classical theism (necessary, immaterial, transcendent creator) and the divinities of the Greek or Hindu pantheon (contingent, anthropomorphic, finite beings located in space). Comparing the two commits another category of error. Placing on the same level the most perfect being one can conceive and contingent creatures with anthropomorphic attributes is, according to Lavagna, a category mistake^[75].

"The Sixteen-Sided Triangle"

Durand claims that one can no more prove God's nonexistence than that of some far-fetched object:

"Could one rule on the existence of a sixteen-sided triangle, invisible, located outside space-time, and fiercely in love with all music-loving forks with Capricorn rising? Surely not." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 241^[76]

The analogy is deceptive because the invented object is internally contradictory:

• one can demonstrate the nonexistence of a sixteen-sided triangle: by geometrical definition, a triangle has three sides;
• one can demonstrate the nonexistence of a geometrical figure located outside space (geometry presupposes a space);
• a music-loving fork is an internal contradiction (a fork has no nervous system capable of music-love).

None of these criteria applies to the classical concept of God, which is neither internally contradictory nor denied by the sciences. "One could perfectly well rule on its falsity, if the concept were illogical. But it is impossible to demonstrate its internal incoherence," concludes Lavagna^[77].

"No Proof" and "Insufficient Proof" Are Not the Same Thesis

A good part of debates about God's existence spins idly for a purely lexical reason. Bolloré and Bonnassies formulate it with a sharpness worth preserving as is:

"He may possibly consider that the proofs presented here do not suffice to make him change his mind, but it is difficult to maintain that there are none." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 498^[78]

In ordinary English, "proof" can denote an argument, a clue, or a converging datum; in a strict sense, it denotes a constraining demonstration. When a zetetician repeats "there is no proof," one must ask which of the two senses he means: if he means that no public argument exists, the claim is false — dozens exist, discussed for twenty-five centuries by the greatest philosophers. If he means that none of these arguments rationally compels him to change his mind, that is an admissible position, but it is no longer the same claim, and it must be formulated as such.

Refuting an Argument Does Not Prove the Contrary Thesis

Symmetrically, showing that a particular theist argument fails does not prove atheism — any more than showing that a particular atheist objection fails proves theism. The authors of Dieu, la science, les preuves themselves acknowledge this about a materialist objection they examine:

"This reasoning does not claim to be a direct proof of God's nonexistence, but the refutation of a proof of his existence — although, by a poorly justified leap, it then arrives at the conclusion of God's nonexistence." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 510^[79]

It is a rule that should discipline the whole debate: the burden of proof follows the proposition actually affirmed, not the camp that speaks last. The theist who affirms "God exists" carries a burden; the propositional atheist who affirms "God does not exist" carries one too; the agnostic who suspends judgment carries a burden only for his own additional affirmations (impossibility, incoherence, total absence of evidence)^[80].

A Cumulative Case Is Audited, Not Piled Up

The idea of a converging bundle of independent proofs is methodologically sound — it was already encountered above with the Catechism and Swinburne. But it is sometimes invoked with a one-way demand:

"For if, in logic, a single valid proof suffices to validate a thesis, conversely, to demonstrate that a thesis is false […], it is necessary to prove that all the proofs put forward are false." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 517^[81]

This formula unduly reverses the burden: to show that a file of ten arguments does not demonstrate its conclusion, the opponent does not need to prove false each of the ten facts mentioned — it suffices to show that each line of argument contains at least one insufficiently established premise or an inference that does not necessarily follow. A genuinely cumulative case is cumulative only if its branches are truly independent: cosmology, fine-tuning, mathematical intelligibility, and moral experience are not four totally separate proofs if they rest, in part, on the same underlying metaphysical premises. An honest bundle is audited branch by branch; it is not piled up to impress.

Militant zetetics and the New Atheism share a definition of faith that corresponds neither to what Christianity calls faith nor to what philosophers call rational belief.

The Atheist Definition of Faith

For Durand, faith would literally be blind credulity:

"Having faith certainly has a novelistic, romantic, aesthetic aspect; it is hoping beyond reason that an idea impossible to prove will finally, in one way or another, prevail. […] It is siding with every superstition, with magical thinking, with obstinacy against facts, with rejection of method, with guru-speak gibberish, with demagogic promises and fundamentalist impulses; it is delivering oneself body and soul to the good pleasure of cynical manipulators or sincere illuminati whose fervor cannot replace prudence, self-criticism, the taste for arguing pros and cons. […] From an epistemic point of view, faith is not a virtue, any more than it is an advantage for examining the world objectively, effectively, and rationally." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 337^[82]

It is a caricatural definition that Christian theologians never recognized. It confuses theological faith with credulity.

The Catholic Faith as an Act of Reasoned Trust

To present the doctrine, Lavagna proposes a convenient pedagogical threefold division of the word faith (p. 37, n. 25 — reference given subject to verification against the printed copy)^[83]:

Saint Thomas, for his part, does not divide faith into these three senses: in the Summa Theologiae (IIa-IIae, q. 2, a. 2), he analyzes one and the same act of faith according to three relations to its object — believing God (credere Deo: adhering to the First Truth as the formal motive of assent), believing about God (credere Deum: holding as true the object proposed, God and what He reveals), believing in God (credere in Deum: tending toward God as toward one's end, under the motion of the will)^[84].

"Faith is an act of the intellect assenting to divine truth under the command of the will moved by God through grace." — Saint Thomas Aquinas, Summa Theologiae, IIa-IIae, q. 2, a. 9, corp.^[85]

None of these three senses is "believing without any reason what is affirmed by someone who speaks without knowledge." Authentic Catholic faith has always been understood as a rationally justified act, founded on exterior motives of credibility (miracles, prophecies, the transformation of the apostles, the holiness of the saints, the historical fruitfulness of the Church) that render adherence reasonable even before the interior gift of grace. That is the solemn teaching of the First Vatican Council, in the dogmatic constitution Dei Filius (24 April 1870):

"But, in order that the submission of our faith might be in accordance with reason, it was God's will that there should be joined to the interior helps of the Holy Spirit exterior helps of his revelation — namely, divine facts, and above all miracles and prophecies, which, showing forth God's omnipotence and infinite knowledge, are most certain signs of divine revelation, suited to the understanding of all." — First Vatican Council, Dei Filius, ch. 3, De Fide, 24 April 1870 (Denzinger 3009)^[86]

The Parachute Analogy (Timothy McGrew)

The epistemologist Timothy McGrew (Western Michigan University) proposes a limpid analogy taken up by Lavagna:

"You are about to jump out of an airplane with an instructor, wearing a parachute. The probability that you come through it is very high. Rationally, you know you have a 99.99% chance of landing safe and sound. But before throwing yourself out of the plane, you still need that 'act of faith' in the quality of the instructor and his equipment. This analogy shows well that having faith is not believing blindly. It is rather an act of trust and hope which, to be serious, must be rationally founded." — Matthieu Lavagna (reporting Timothy McGrew), Les travers de la zététique, Salvator, 2023, p. 36^[87]

The analogy illuminates one precise point — and only it: exterior motives of credibility can render reasonable an act of trust that remains free. It does not say everything about theological faith: in the latter, the formal motive of assent is not the reliability of the instructor, but the authority of God who reveals, received under the motion of grace (cf. Vatican I, quoted above). The believer does not jump blindly into the void; he has solid reasons (philosophical, historical, experiential) that render the act of trust rationally justified — but there remains, at the end of the course, an act of trust, of self-surrender.

Theological Faith Remains Free, Even Before Proofs

A frequent zetetician objection:

"If God reveals himself to the believer, appears to him, speaks to him, there is no longer any question of sparing his freedom not to believe." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 173^[88]

This shows a confusion between knowing that someone exists and believing in him. Christian theology affirms:

"You believe in the one God — that is creditable enough, but even the demons have the same belief, and they tremble with fear." — Saint James, Epistle, 2, 19^[89]

Demons do not doubt God's existence — they know it better than we do. Yet they refuse theological faith, which is not a forced intellectual assent but a free act of self-surrender. That is why the First Vatican Council anathematizes the idea that faith would be necessitated by reason:

"If anyone shall say that the assent of Christian faith is not free, but is necessarily produced by the arguments of human reason […], let him be anathema." — First Vatican Council, Dei Filius, canons on faith, 3 (Denzinger 3035)^[90]

The zetetician argument that proofs would destroy faith falls flat: proofs render faith reasonable, but faith remains a free act of the will, which can be refused.

Believing Does Not Prevent Understanding

Another zetetician confusion:

"Believing prevents understanding why one believes." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 310^[91]

This claim is factually false. Saint Anselm, in the eleventh century, formulated the inverse program — fides quaerens intellectum, faith seeking understanding^[92]. Saint Thomas Aquinas, in the thirteenth century, distinguished in the Summa contra Gentiles between "truths of reason" (accessible to natural philosophy) and "revealed truths" (which surpass reason without contradicting it), showing how the two can coexist harmoniously^[93].

The history of Christian theology — from the second-century apologist Fathers (Justin, Athenagoras) to Newman and Garrigou-Lagrange — is that of a faith that seeks to understand, that asks for reasons, argues, demonstrates. Not the reverse.

Confusing Knowledge and Belief

Another zetetician confusion consists in opposing belief (presumed subjective and irrational) to knowledge (presumed objective and scientific). Philosophers define:

This definition is attributed to Plato (Theaetetus) and remains, since Edmund Gettier's founding 1963 article, the basis of contemporary analytic epistemology^[94]. In simple words: Gettier showed by counterexamples that a belief can be true and justified by accident, without being genuine knowledge — Plato's definition is therefore necessary, but not always sufficient. Direct consequence: even the most certain truths are justified beliefs. "1 + 1 = 2" is a belief — but it is a true and justified belief, hence knowledge. "Napoleon existed" is a belief — but it is knowledge, founded on converging historical sources. I know is a particular species of the genus I believe^[95]. Religious belief is therefore not, by essence, on the side of soft subjectivity.

A common zetetician objection:

"I defend a humble position which consists in saying that, in the absence of objective proof, it is not reasonable to 'believe' in the existence of an entity that no one has seen." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 23-24^[96]

The argument seems reasonable. It is not.

God Is Invisible by Nature

Classical theism defines God as immaterial, transcendent, non-spatial. He is not an object of the world, nor an entity among other entities. He is the uncaused cause of all finite existence^[97]. Demanding to see Him with the eyes of the body is therefore committing a category mistake: one asks an immaterial object to meet the criteria of a material object. It is as absurd as asking for the color of the square root of 2.

Many Important Realities Are Not Seen

If one accepted only visible realities, one would have to reject:

• love (no one has ever seen it);
• friendship, justice, truth;
• virtues, moral values;
• mathematical laws;
• physical laws themselves (we observe their effects, never themselves).

The "I believe only what I see" argument does not survive examination: consistently applied, it would force us to reject realities its own defender admits — love, justice, mathematical laws.

The Proofs of God's Existence: Converging Arguments

The Catechism of the Catholic Church specifies how knowledge of God by natural reason is to be understood:

"Created in God's image and called to know and love him, the person who seeks God discovers certain ways of coming to know him. These are also called proofs for the existence of God, not in the sense of proofs in the natural sciences, but rather in the sense of 'converging and convincing arguments', which allow us to attain certainty about the truth. These 'ways' of approaching God from creation have a twofold starting point: the physical world, and the human person." — Catechism of the Catholic Church, § 31^[98]

The keyword is converging. The strength of the theist case lies not in a single shattering proof (which would be formally unverifiable in the narrow sense of the term), but in the cumulative convergence of several independent arguments: contingency, causality, fine-tuning, mathematical order, consciousness, free will, moral experience, religious experience, historical testimonies of the Resurrection. See The Proofs of God's Existence — Synthesis.

The Concept of God Is Very Precisely Defined

Durand claims moreover that the concept of God is vague:

"'Define for me what you mean by God and I will tell you whether I believe in it.' Only, this definition is still not settled, and the serious dialogue we could have, in order to put this omnipresent concept to the test, cannot take place." — Thomas Durand (quoting a distorted Einstein), Dieu, la contre-enquête, Humensciences, 2022, p. 343^[99]

Lavagna replies:

"The concept of God is among the best defined there are. For centuries, all philosophers, atheists or theists, have agreed on a perfectly stable composite portrait: God is defined as the first cause of everything that is not him — a unique cause, transcendent — that is, distinct from the Universe —, immaterial, intelligent, eternal." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 31^[100]

The philosophical tradition distinguishes three families of definitions:

Saint Anselm, in the Proslogion (1077-1078), gives a formula that became classical:

"God is that than which nothing greater can be thought." — Saint Anselm of Canterbury, Proslogion, ch. 2^[101]

Saint Thomas Aquinas shows how this "perfect being" can also be called ipsum esse subsistens — the pure act of being subsisting through itself^[102]. In simple words: God does not have existence as creatures received it; He is Existence itself, existing through Himself without having received it from anyone.

Beyond argumentative objections, militant atheism suffers from an often concealed psychological trait: an a priori lock-in that immunizes the position against any new fact. Several leading atheists publicly admitted it.

Thomas Nagel's Admission

The philosopher Thomas Nagel (New York University), one of the most respected atheists of the twentieth century, writes with rare honesty — a passage Lavagna reproduces verbatim as a central exhibit:

"I speak from experience, being strongly subject to this fear myself: I want atheism to be true and am made uneasy by the fact that some of the most intelligent and well-informed people I know are religious believers. It isn't just that I don't believe in God and, naturally, hope that I'm right in my belief. It's that I hope there is no God! I don't want there to be a God; I don't want the universe to be like that. My guess is that this cosmic authority problem is not a rare condition and that it is responsible for much of the scientism and reductionism of our time." — Thomas Nagel, The Last Word, Oxford University Press, 1997, p. 130-131^[103]

The admission is not a philosophical refutation of atheism — Nagel remains an atheist. But it disarms the zetetician claim to represent pure neutral reason. If one of the greatest contemporary atheists recognizes a desire that God not exist, militant zetetics can no longer claim the monopoly of objectivity.

George Wald: "There Is No Third Position"

More radical still, the biologist George Wald (1906-1997), professor at Harvard and 1967 Nobel laureate in medicine, wrote in 1954 in Scientific American:

"The reasonable view was to believe in spontaneous generation; the only alternative, to believe in a single, primary act of supernatural creation. There is no third position. […] One has only to contemplate the magnitude of this task to concede that the spontaneous generation of a living organism is impossible. Yet here we are as a result, I believe, of spontaneous generation." — George Wald, "The Origin of Life," Scientific American, August 1954, p. 48^[104]

The admission is sober and established on record: faced with his own dilemma, Wald retains the hypothesis whose implausibility he has just himself established. (The expanded version of this remark, sometimes attributed to an address at the Bombay congress in January 1986, has not been found on record: it is not reproduced here.) This is not an argument against atheism — but it is the end of the zetetician claim to be an epistemology of pure reason.

Such an a priori lock-in — refusing in advance any fact that would contradict atheism — would be the exact opposite of the zetetician claim to "follow the evidence wherever it leads." The Gospel described this closure two thousand years earlier:

"If they will not listen either to Moses or to the prophets, they will not be convinced even if someone should rise from the dead." — Gospel according to Saint Luke, 16, 31^[105]

Two Documented Cases, Not a Universal Verdict

From these two written admissions, Lavagna formulates, in the section "The Problem of Reasonable Unbelief" (Les travers de la zététique, Salvator, 2023), the following hypothesis: faced with the convergence of rational arguments for theism and the mass of documented miracles (Lourdes, Fatima, Calanda, Pierre de Rudder, Francis Pascal, Bruce Van Natta, Eucharistic miracles), persistence in atheism would be explained, according to him, either by insufficient examination of the arguments, or by unfamiliarity with the files, or by a voluntary resistance of the will — the Nagel and Wald cases illustrating this third case^[106].

This hypothesis never replaces the examination of arguments: it proves nothing about God's existence, and it legitimately describes only cases documented by written admission — Nagel and Wald. Extending it, without such an explicit admission, to every persistent atheist interlocutor would amount to psychoanalyzing his belief exactly as Durand psychoanalyzes the believer's faith — the same procedure this article has just qualified as a genetic fallacy. It therefore remains legitimate as a description of documented cases, never as a universal verdict projected onto an interlocutor who has shown no resistance of this type.

Pascal, two centuries earlier, had formulated exactly the same intuition:

"There is enough light for those who desire only to see, and enough darkness for those who have a contrary disposition." — Blaise Pascal, Pensées, fragment 430 Brunschvicg^[107]

The miracle of the sun at Fatima (13 October 1917) constitutes a textbook case for militant zetetics: if an honest method cannot examine it without prejudice, it reveals its limits. Lavagna devotes a whole appendix to it (p. 186-202).

The Attested Historical Facts

Three illiterate little shepherds — Lucia dos Santos (10 years old), Francisco Marto (9 years old), and Jacinta Marto (7 years old) — announce three months in advance a spectacular sign to take place on 13 October 1917 at Cova da Iria, near the village of Fatima in Portugal. This announcement prior to 13 October is documented by the interrogations of the children preserved and published in the Documentação Crítica de Fátima (Santuário de Fátima, 2013), including those conducted by Dr. Manuel Nunes Formigão from 27 September 1917 onward^[108].

On 13 October, several tens of thousands of people are on site — estimates vary, most often between 30,000 and 70,000 — including journalists and onlookers hostile to Catholicism. Among them, Avelino de Almeida, editor-in-chief of the great liberal daily O Século, who had shown irony toward the apparitions and had come to "debunk Fatima." At the appointed moment, the sun seems to "dance," changes colors, appears to fall upon the crowd. Clothes and ground soaked by the morning rain dry, according to witnesses, within minutes. The phenomenon is also reported several kilometers around, notably at Alburitel. O Século publishes the account of the event on 15 October from the pen of the same Almeida, who reports what he declares he saw^[109].

The Seven Hypotheses Examined

Durand, true to his method, refuses to examine the file seriously. He oscillates between collective hallucination, retinal persistence, and even the extraterrestrial hypothesis^[110]. Lavagna soberly lists the seven possible hypotheses and shows that all naturalistic hypotheses simultaneously fail^[111]:

A particularly revealing case: Durand prefers to support the extraterrestrial hypothesis rather than a Marian miracle. He cites Rear Admiral Pinon's thesis that "the virginal aspect of the phenomenon would be a deliberate camouflage on their [the extraterrestrials'] part" and explicitly concludes:

"If one had to bet on these two possibilities to the exclusion of all others — either the Virgin or the extraterrestrials — the zeteticians, the skeptics, and the majority of rationalists would take the extraterrestrial option." — Thomas Durand, Dieu, la contre-enquête, Humensciences, 2022, p. 205^[112]

Preferring extraterrestrials disguised as the Virgin appearing to illiterate shepherds over the simple Marian hypothesis is no longer rationalism: it is the admission of a materialist presupposition that renders any supernatural conclusion impossible a priori.

The Epistemic Cost of Refusal

Refusing the miracle of Fatima thus forces one to pile up ad hoc hypotheses, each less probable than the Marian hypothesis. That is exactly the opposite of the method of Occam's razor, which zetetics nevertheless claims to practice.

"All the alternative explanations he proposes are ad hoc and scarcely credible. His scientism and materialism prevent him from considering for a single second that there might be a unifying hypothesis that could simply account for all the facts: a miracle worked by Mary, for the conversion of hearts." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 202^[113]

The Method of Inquiry: Three Distinctions That Zetetics Blurs

Three rules of inquiry, drawn from the examination of the same file by Bolloré and Bonnassies, deserve to be stated separately, for they discipline skeptical excess as much as apologetic excess.

An announcement recorded before the event weighs more than a concordance noted after the fact. The three shepherds announce the prodigy three months in advance, and this announcement is put in writing by third parties before 13 October^[114]. Bolloré and Bonnassies sum up the criterion in one sentence: "It was announced long in advance"^[115]. This criterion has value only if the announced text is sufficiently precise and its anteriority authenticated — which is the case here, but which must always be verified file by file, not assumed.

The factual core must be separated from its causal explanation. Newspapers hostile to Catholicism, present at Fatima precisely to debunk the phenomenon, likewise report that "there did indeed occur a major event that everyone saw, though it remains to be known which one and to determine its cause"^[116]. This is the most solid distinction in the whole file: ideologically opposed sources can converge on what was observed while diverging on its cause. Inquiry must establish each separately — and an accumulation of press articles reprinting the same dispatch is not worth as much as several genuinely independent testimonies.

Competing hypotheses do not add up as if they formed a single proof. Piling up fraud, retinal persistence, hallucination, and an unknown meteorological phenomenon — four otherwise largely incompatible explanations — does not increase their cumulative probability^[117]. A genuine "collective hallucination" in the strict psychiatric sense — an identical and simultaneous deregulation in tens of thousands of different brains, without any objective external stimulus — is, in fact, just about impossible to defend^[118]. But that does not suffice to eliminate, in a single gesture, a perceptual illusion founded on a common stimulus, attentional contagion, or convergent memorial reconstruction: these are distinct hypotheses, which the article must name separately rather than grouping them under a single fuzzy label of "hallucination."

For the complete file: see Our Lady of Fatima — The 1917 Apparitions and Discerning Supernatural Phenomena.

A Catholic encyclopedia that denounces the fallacies of militant zetetics cannot allow itself to tolerate the same fallacies in its own allies. Yet Dieu, la science, les preuves — a work precious for the mass of data and citations it gathers — itself commits, on several occasions, exactly the errors it reproaches in its adversary. Pointing them out here does not weaken the theist case: it strengthens it, by distinguishing what stands up to rigorous examination from what belongs to rhetoric.

The Symmetrical False Dilemma

The zetetician who reduces everything to "natural explanation or credulity" commits a false dilemma. But the apologist who reduces a striking singularity to "chance or revelation" commits the same error, in reverse:

"There is, however, not much room between the two possible explanations: the one that sees there the fruit of chance alone and the one that recognizes in it a divine revelation." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 328^[119]

Between pure chance and direct revelation, there is nevertheless a whole space of intermediate hypotheses — cultural evolution, borrowings, retrospective selection of striking facts, combinations of natural causes and ordinary providence — which must be examined before being set aside, not bypassed by a two-branched dilemma. The rule is symmetrical: neither the zetetician nor the apologist has the right to reduce the space of explanations to two boxes in order to force the conclusion they prefer.

Rhetorical Probabilities: Five Questions Before Yielding to a Figure

Claiming that a chain of facts lies "outside all reasonably imaginable probabilities"^[120] is a frequent rhetorical device on both sides of the debate — in the zetetician who declares a miracle statistically impossible without ever calculating anything, as in the apologist dazzled by a striking coincidence. For an improbability to become an argument, five conditions must be specified:

Without these specifications, a feeling of astonishment disguises itself as calculation. This demand does not dissolve the cosmological fine-tuning argument, correctly formalized by cosmologists themselves — see Cosmological Fine-Tuning — but it forbids imitating its form without its rigor.

Hostile Testimony Has Value — But Not "Necessarily" More Than Others

"This thesis is untenable, for the historical reality of Jesus is very well established, if only by the mentions made of him by his many detractors. And hostile testimonies necessarily carry more probative value than those of his faithful." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 363^[121]

A hostile testimony is precious when its author concedes a fact contrary to his own interest or his own program: that reduces the hypothesis of concerted collusion or propaganda. But hostility in itself guarantees neither competence, nor direct access to facts, nor the source's independence from its own rumors. Its probative value depends on the witness's proximity, the chain of transmission, the precision of the account, and its corroboration by other sources — not on its author's mere declared hostility.

Martyrdom, Sincerity, Competence, Truth: Three Notions Not to Be Confused

"I believe witnesses who get their throats cut." — Blaise Pascal, Pensées, bundle on miracles (formulation taken up by Bolloré and Bonnassies, p. 392; fragment numbering varies by edition — Brunschvicg, Lafuma, Sellier — so no number is given here)^[122]

Accepting death for a testimony strongly establishes the witness's sincerity — especially if he was in a position to know he had fabricated the account himself. It does not by itself establish his competence (did he correctly perceive and report the facts?), nor the complete truth of his interpretation. The formula is memorable in three steps: martyrdom attests sincerity; proximity attests competence; corroboration attests the truth of the fact. Confusing the three turns a real clue into a proof it does not, by itself, suffice to bear.

Morality and Evolution: A Genealogy Is Not a Verdict

The biologist Michael Ruse proposes a purely evolutionary explanation of our moral sense:

"Morality, or more exactly our belief in morality, is nothing but an adaptation put in place to realize our reproductive ends." — Michael Ruse, quoted by M.-Y. Bolloré and O. Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 473^[123]

The "or more exactly" is revealing: natural selection can propose a genealogy of our moral belief without demonstrating that the object of that belief is illusory — that is exactly the error of the genetic fallacy already encountered in Durand, applied this time to morality rather than faith. But the apologist commits the inverse fallacy in presenting the question as a closed dilemma:

"There are only two possibilities here: either you believe that an absolute good and evil exist and then you are obliged to believe in God, or you refuse to believe it and you must, for consistency, assume your Darwinian materialism and everything that goes with it." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 474^[124]

Theism offers a solid ontological foundation for moral objectivity — see The Answer to Evil and Suffering — but the existence of non-theist moral realisms, however fragile, must be presented loyally before being criticized, not set aside by a two-branched dilemma presented as exhaustive.

A crucial distinction, often neglected by militant zetetics, separates two theses that must be kept distinct:

The naturalistic method is legitimate in the laboratory — a biologist does not appeal to God to explain a chemical reaction. But the naturalistic method does not demonstrate metaphysical naturalism^[125]. Confusing the two is the central error of zetetician scientism. The undeniable success of the naturalistic method in a limited domain (repeatable, measurable phenomena in the physical world) gives no justification for claiming that nothing exists beyond that domain.

It is exactly like a physicist saying: "My detector captures only electromagnetic waves. Therefore only electromagnetic waves exist." The argument is manifestly absurd. The method defines what it can detect; it does not exhaust what exists.

As the philosopher Alvin Plantinga writes in Where the Conflict Really Lies (Oxford UP, 2011), "the real conflict is not between science and religion, but between science and metaphysical naturalism"^[126]. Science presupposes the reliability of human reason — a reliability that metaphysical naturalism, paradoxically, cannot guarantee, since it makes our cognitive faculties depend on a blind evolutionary process whose goal is not truth but survival.

The Big Bang Feeds the Cosmological Argument; It Does Not Measure Creation

The most frequent symmetrical error among Big Bang apologists consists in confusing a very solidly corroborated cosmological model with a direct observation of the creative act. The standard model describes an extremely hot and dense primordial state, expanding for about 13.8 billion years^[127]; that is a result of physics, not a measurement of nothingness. The priest-physicist Georges Lemaître, who proposed the "primeval atom" hypothesis as early as 1931, had himself taken care to separate cosmological calculation from any theological trial of intent:

"We can conceive that space began with the primeval atom and that the beginning of space marked the beginning of time." — Georges Lemaître, quoted by M.-Y. Bolloré and O. Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 88^[128]

The Big Bang makes the philosophical question of a beginning of the universe serious and pressing — a real contribution to the Kalam Cosmological Argument. But it does not prove, by itself, a creation ex nihilo in the theological sense: the initial singularity marks above all the limit of application of the equations of general relativity, not an observation of absolute nothingness. Some physicists, moreover, explicitly admitted that their resistance to the model stemmed from an avowed philosophical unease rather than empirical disagreement:

"Philosophically, I find the notion of a beginning to the present order of nature repugnant." — Arthur Eddington, quoted by M.-Y. Bolloré and O. Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 88^[129]

Eddington's admission cuts both ways: it shows that a scholar can himself distinguish his philosophical objection from an empirical refutation — which should prompt the same prudence in the apologist hasty to turn a cosmological model into a demonstration of Genesis.

The same principle of prudence applies to the older argument drawn from the unexplained effectiveness of mathematics in describing the physical world — from Wigner to Paul Davies. Bolloré and Bonnassies sum up the reasoning as a direct inference:

"If the world was not designed by an intelligence, the applicability of mathematics is a coincidence. […] Yet it is very improbable that the applicability of mathematics is a coincidence." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 487^[130]

The fact to be explained is real and philosophically serious; but the inference skips a step by presenting coincidence and creative intelligence as the only two options, without mentioning the competing positions (nomological necessity, non-theist mathematical realism, anthropic selection) that would first have to be set aside. A fact to be explained remains a fact to be explained, not yet a demonstration. The same excess of confidence threatens the contingency argument when it slides too quickly from an earlier physical state to the existence of the totality:

"By thus referring from cause to cause to infinity, we do not explain the existence of the Universe; we explain only its transformations." — Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves, Guy Trédaniel, 2021, p. 489^[131]

The distinction is decisive and must structure every serious use of the Contingency Argument: explaining one state of the universe by an earlier state, however far back up the chain, never answers the question of why there exists a totality rather than nothing. That does not yet establish that this question has a personal causal answer; it only forbids claiming that a regression of physical states has already resolved it — in either direction.

We return here to the heart of the case. If atheism is the affirmation that God does not exist, then it is a belief — a positive thesis about reality — which must be defended by arguments. What are the militant atheists' arguments?

The Logical Problem of Evil: Defused by Plantinga

The best-known atheist argument is the logical argument from evil: if God were omnipotent, omniscient, and good, there would be no evil in the world. Yet there is evil. Therefore God does not exist.

This argument was definitively refuted by the philosopher Alvin Plantinga (University of Notre Dame) in God, Freedom, and Evil (1974), via the free-will defense: God may have morally sufficient reasons for permitting evil — for example to preserve human freedom, the condition of genuine love^[132]. Even leading atheists now recognize this. J. L. Mackie, who had defended the logical version of the problem, ended up conceding:

"We can concede that the problem of evil does not, after all, show that the central doctrines of theism are logically inconsistent with one another." — J. L. Mackie (atheist philosopher), The Miracle of Theism, Oxford University Press, 1982, p. 154^[133]

William Rowe, another atheist of reference, writes in the same vein:

"Some philosophers have contended that the existence of evil is logically incompatible with the existence of the theistic God. No one, I believe, has succeeded in establishing such an extravagant claim." — William Rowe (atheist philosopher), quoted in Lavagna, p. 62^[134]

William P. Alston concludes: "It is now almost universally accepted that the logical problem of evil has been refuted."^[135] The evidential version (which raises serious questions) remains, but it is compatible with God's existence: see The Answer to Evil and Suffering and Love, Freedom, Evil and Hell.

God's Silence (the Hiddenness Argument)

John L. Schellenberg proposes the "hiddenness" argument: if God existed and loved us, He would manifest Himself clearly to all, and there would be no sincere unbelievers. Yet there are sincere unbelievers. Therefore God does not exist^[136]. Here again, the argument is largely answered by Catholic theology: God manifests Himself to the measure that man makes himself available, and preserves the freedom of faith (cf. Vatican I); divine "hiddenness" is itself an effect of God's delicacy toward our freedom.

Lavagna replies precisely by pinpointing the argument's logical flaw: it would require "a rational human being, well informed and of good will, who is not brought to believe in God throughout his life"^[137], yet the premise becomes empirically hard to sustain once the corruption of the will and the affective resistance before God brought to light by Nagel and Wald are admitted.

The Other Atheist Arguments Are Weak or Inoperative

The rest of the atheist case often boils down to:

• objections to the biblical model of creation (which assume a fundamentalist reading that classical Catholicism does not defend — see Adam and Eve, Historicity);
• moral objections (which assume an objective moral standard… which does not hold within strict materialism — cf. the Euthyphro dilemma turned back on itself);
• sociological objections (which are genetic fallacies);
• Freudian psychological objections (already defused above).

Once these objections are defused, positive atheism no longer has any decisive argument left. It becomes a mere intellectual preference. That is what brings it back to the rank of belief — in the strong sense of the word.

The Militant Atheist's Final Dilemma

"One cannot say things like 'atheism is true' or 'atheism is false,' for an absence of belief reflects no propositional content about reality, but a mere psychological state in which a person finds himself." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 50^[138]

If the atheist wants to maintain that his position is true (and not a subjective mental state), he must accept that it is a belief and therefore demands a foundation. That is precisely what militant zeteticians refuse. They want both:

• to present their position as the only rational one (hence as a truth);
• not to have to justify it (by presenting it as a mere absence of belief).

That is intellectually untenable. Sooner or later, militant atheism must choose: either it owns itself as a positive affirmation and accepts the burden of proof; or it collapses into mere epistemic agnosticism.

The Catholic Church has addressed these questions several times over the past centuries, with remarkable consistency.

Vatican I (1870): God Can Be Known by Natural Reason

The First Vatican Council solemnly affirms the possibility of knowing God by the light of reason, before any gift of faith:

"Holy Mother Church holds and teaches that God, the beginning and end of all things, can be known with certitude by the natural light of human reason from created things." — First Vatican Council, Dei Filius, ch. 2, De Revelatione, 24 April 1870 (Denzinger 3004)^[139]

This affirmation is dogmatic. It means that the rationality of faith is not a Catholic opinion but a truth of faith: human reason is capable, in theory, of arriving at God without exterior intervention. That is not a concession to rationalism; it is a defense of reason against fideism.

Pius XII (1950): Humani Generis

Pope Pius XII confirms this teaching in the encyclical Humani Generis (12 August 1950):

"Indeed, the human mind at times finds it difficult to formulate even a certain judgment of 'credibility' concerning the Catholic faith, although God has provided a great number of most striking exterior signs by which we can prove, with certainty, the divine origin of the Christian religion with the natural lights of our reason alone." — Pope Pius XII, Humani Generis, 12 August 1950, § 2 (official vatican.va text, verified against the original)^[140]

The teaching is limpid: not only can reason know God's existence, but it can also recognize the credibility of Christian revelation through the rational examination of the signs (miracles, prophecies, testimonies, holiness, historical fruitfulness).

John Paul II (1998): Fides et Ratio

The encyclical Fides et Ratio (14 September 1998) is probably the most important magisterial text of the twentieth century on the question. Saint John Paul II defends there the legitimacy of natural reason against fideisms, the legitimacy of faith against scientism and narrow rationalism, and their complementarity: faith enriches reason, and reason purifies faith. The incipit became famous:

"Faith and reason are like two wings on which the human spirit rises to the contemplation of truth." — Saint John Paul II, Fides et Ratio, incipit, 14 September 1998^[141]

And the pope criticizes precisely reason reduced to experimental data — a passage that could have been written for today's French militant zetetics:

"This philosophical conception refuses to admit as valid forms of knowledge other than those proper to the positive sciences, relegating religious and theological knowledge, as well as ethical and aesthetic knowledge, to the realm of pure imagination. […] It must unfortunately be noted that scientism regards as irrational or imaginary whatever touches on the question of life's meaning." — Saint John Paul II, Fides et Ratio, § 88, 14 September 1998 (official vatican.va text, verified against the original)^[142]

This criticism targets not science — which is legitimate and precious — but the philosophical claim of scientism to occupy the whole space of knowledge.

Catechism of the Catholic Church: §§ 156-159

The Catechism synthesizes the traditional teaching on the harmony between faith and reason:

"Though faith is above reason, there can never be any real discrepancy between faith and reason. Since the same God who reveals mysteries and infuses faith has bestowed the light of reason on the human mind, God cannot deny himself, nor can truth ever contradict truth." — Catechism of the Catholic Church, § 159 (quoting Vatican I, Dei Filius, DS 3017)^[143]

The magisterial conclusion is clear: there is not, cannot be, and never will be any genuine conflict between true science and authentic Catholic faith. All apparent conflicts come either from a poor understanding of science (Catholics drawing from the Bible scientific theses it does not support), or from a poor understanding of faith (atheists caricaturing what the Church really teaches).

Zetetics-as-method is not only compatible with Catholicism: it is an objective ally of it when it combats charlatans, superstitions, and pseudo-sciences. Zetetics-as-metaphysics, by contrast, is not a scientific approach: it is a particular philosophy (scientism + metaphysical naturalism + New Atheism) that must be rationally defended as such and cannot hide behind the authority of science.

What should be retained from all this?

Militant atheism, when consistent with itself, is a positive affirmation about reality — God does not exist — which carries the same burden of proof as any philosophical thesis. Affirming "God does not exist" is as committing as affirming "God exists." Neither thesis is the neutral default option. The only neutral position is honest epistemic agnosticism, which says "I do not know; let us examine the arguments."

The authentic Catholic, for his part, does not refuse methodical doubt — he welcomes it. He verifies his sources, examines objections, accepts true science, refuses superstition. But he refuses dogmatic doubt: the bad skepticism that forbids in advance any conclusion falling outside the materialist framework.

"Reality is not binary. Even if there were no absolute and definitive proof of God's existence, the presence of a bundle of converging and independent proofs would suffice to make the rational man admit that theism is far more probable than atheism." — Matthieu Lavagna, Les travers de la zététique, Salvator, 2023, p. 46^[144]

Saint Peter, in his first epistle, gives the apologetic program of all time:

"Simply proclaim the Lord Christ holy in your hearts, and always have your answer ready for people who ask you the reason for the hope that is in you — but with courtesy and respect." — Saint Peter, First Epistle, 3, 15-16^[145]

The Catholic faith asks for reasons; it gives them. It never reduces to a leap into the void; it is a knowledge higher than natural experience but not contradicting it. That is exactly the opposite of naive credulity. Christianity does not ask the reader to believe without reasons: it asks him to examine the reasons, seriously, without prejudice, and to respond freely to the call of the God who reveals Himself.

Saint Augustine formulates the disposition of heart that argumentation alone cannot produce, but without which it remains inoperative:

"You have made us for yourself, O Lord, and our heart is restless until it rests in you." — Saint Augustine, Confessions, Book I, ch. 1^[146]

• The Proofs of God's Existence — Synthesis
• The Contingency Argument — Leibniz and the Uncaused Cause
• Cosmological Fine-Tuning
• The Kalam Cosmological Argument
• The Answer to Evil and Suffering
• Love, Freedom, Evil and Hell
• Discerning Supernatural Phenomena
• The Miracles of Lourdes
• Our Lady of Fatima — The 1917 Apparitions
• Have Studies Proven Prayer Ineffective?
• Jesus of Nazareth — Historical Existence
• Adam and Eve, Historicity

Main Sources

• Matthieu Lavagna, Les travers de la zététique — Réponse au livre de Thomas Durand « Dieu, la contre-enquête », MDN Productions / Salvator, Paris, December 2023, 254 pp.
• Thomas Durand, Dieu, la contre-enquête, Humensciences, Paris, 2022, 360 pp.
• Michel-Yves Bolloré and Olivier Bonnassies, Dieu, la science, les preuves — L'aube d'une révolution, Guy Trédaniel, Paris, 2021, 576 pp., ISBN 978-2-8132-2585-6.
• First Vatican Council, Dei Filius — Dogmatic Constitution on the Catholic Faith, 24 April 1870.
• Pope Pius XII, encyclical Humani Generis, 12 August 1950.
• Saint John Paul II, encyclical Fides et Ratio, 14 September 1998.
• Catechism of the Catholic Church, §§ 31, 36, 156-159, 2110-2117.
• Saint Thomas Aquinas, Summa Theologiae, Ia q. 2; IIa-IIae q. 2; Summa contra Gentiles, Book I.
• Saint Augustine, Confessions, Book I; De Civitate Dei, Book XI; Contra Academicos.
• Saint Anselm of Canterbury, Proslogion, ch. 2-4.
• Blaise Pascal, Pensées, fragments 418, 430 (Brunschvicg).
• Alvin Plantinga, God, Freedom, and Evil, Eerdmans, 1974; Where the Conflict Really Lies, Oxford UP, 2011.
• Paul Draper, Atheism and Agnosticism, Stanford Encyclopedia of Philosophy.
• Graham Oppy, Arguing About Gods, Cambridge UP, 2006.
• Richard Swinburne, The Existence of God, 2nd ed., Oxford UP, 2004; Is There a God?, Oxford UP, 1996 (French trans. Y a-t-il un Dieu ?, Ithaque, 2009).
• Karl Popper, Logik der Forschung, 1934 (French trans. La logique de la découverte scientifique, Payot, 1973); "Science as Falsification" (1953), in Conjectures and Refutations, Routledge, 1963.
• Edward Feser, The Last Superstition: A Refutation of the New Atheism, St. Augustine's Press, 2008.
• Thomas Nagel, The Last Word, Oxford University Press, 1997.