What is a miracle?

The three Greek words of the New Testament

The authors of the New Testament use three distinct Greek terms to designate what we call "miracles." They do not compete with one another: each term illuminates a different dimension of the same phenomenon.

Σημεῖον (sēmeion), translated as "sign," is the most characteristically Johannine term. It designates the miracle insofar as it reveals a mission or a divine reality^[1]. John speaks explicitly of "these signs written so that you may believe" (Jn 20:31). The sign points beyond itself: it is not valuable for what it is in itself, but for what it signifies — the presence of the Kingdom, the mission of Christ, the mercy of God. This is why certain miracles are performed by Jesus as signs of a deeper reality, and not merely for the benefit of those whom they relieve^[2].

Τέρας (teras), translated as "prodigy" or "wonder," expresses the effect the event produces on the spectator^[3]. It emphasizes the striking character, the astonishment and admiration aroused in the witness. This term always appears in association with sēmeion in the Acts of the Apostles (Acts 2:22; 4:30; 5:12), as though a single word were not enough to express the whole reality: the prodigy astonishes, but the sign instructs.

Δύναμις (dynamis), translated as "power" or "work of power," places the accent on the divine force at work^[4]. This term, which gives Latin virtus and potentia, insists on the supernatural energy deployed, on God's absolute mastery over natural causes. Saint Paul uses it frequently (1 Cor 12:10; Gal 3:5; Heb 2:4) to designate the charism of miracles as a gift of the Holy Spirit.

These three terms are complementary. The theological tradition will hold that a true miracle is at once teras (it astonishes), sēmeion (it signifies), and dynamis (it manifests divine power)^[5].

"In miracles, two things are to be distinguished: the action itself, which surpasses the forces of nature — this is why miracles are given the name of virtues —; and the purpose of miracles, which is to manifest some supernatural reality — from this point of view, they are generally called signs; but because of their excellence, they are called prodigies, insofar as they produce something far beyond." — Saint Thomas Aquinas, Summa Theologiae, IIa-IIae, q. 178, a. 1, resp. ad 3^[6]

Miracle, prodigy, wonder: why the distinction matters

In everyday language, miracle, prodigy, wonder, or extraordinary phenomenon are used as synonyms. Catholic theology, however, distinguishes them precisely^[7].

This dilution is not peculiar to our media age. As early as 1606, the lexicographer Jean Nicot already distinguished the religious use of the word from its figurative use: a true miracle is "a case, the happening of which ravishes into admiration those who see it or hear the account of it, its cause being wholly and purely divine, and not natural"^[8] — whereas common usage, already described by Nicot himself as "by abuse," applies the word to anything surprising without reference to a divine cause.

• A prodigy (from Latin prodigium, portentum) is a striking, astonishing, remarkable event — but it has no religious meaning in itself. A stage magician performs prodigies; the magicians of Pharaoh do so (Ex 7:11-12); false christs and false prophets will do so even before the end (Mt 24:24; 2 Thess 2:9). The prodigy may be demonic, technical, psychological, or simply rare. Astonishment alone does not make the miracle.
• A wonder designates what arouses aesthetic or spiritual admiration without necessarily being supernatural: the beauty of a sunset, the birth of a child, the sudden conversion of a great sinner may be called "wonders" without falling under the miracle in the technical sense.
• The miracle in the proper sense is a meaningful prodigy: an extraordinary event that surpasses the powers of all created nature and that bears a clear, intelligible religious meaning, coherent with the faith of the Church. Without these two dimensions together, there is no miracle in the canonical sense^[9].

This distinction is not a lawyer's nicety: it is the barrier against two constant temptations. On the one hand, taking every prodigy for a miracle (credulity, manipulation, illuminism, false mystics); on the other, refusing the name of miracle to what nonetheless fulfills every condition (rationalism, methodical skepticism, modernist refusal). By speaking of "miracle" sparingly, the Catholic Church keeps the word its cutting edge.

The Hebrew vocabulary of the Old Testament

The Old Testament likewise employs three main terms for God's extraordinary interventions. ÔTH (אוֹת) designates the sign, the mark, the indication of a message or a mission — often a meteorological, cosmic, or medical intervention that accredits a prophet or confirms a promise (Ex 4:8-9; Isa 7:14)^[10]. MÔPHET (מוֹפֵת) designates the prodigy in the strong sense, the spectacular and shattering event that inaugurates a new stage of sacred history — notably at the exodus from Egypt (Deut 26:8; Ex 11:10). NIFLAÔTH (נִפְלָאוֹת) designates the divine wonders in the broad sense, a term that recurs often in the psalms (Ps 77:12; 86:10; 98:1) to celebrate God's omnipotence at work in history.

The Septuagint — the Greek translation of the Old Testament — generally renders môphet as teras and ôth as sēmeion, thereby establishing a lexical bridge between the Hebrew heritage and New Testament writing^[11]. This continuity is not accidental: the evangelists perceive the miracles of Jesus as the fulfillment of the prodigies promised by the prophets (Isa 35:5-6; Isa 61:1; Lk 7:22).

"Miraculum voco...": The Founding Formula

It is Saint Augustine (354–430) who gives the first explicit definition of miracle in the Western theological tradition. In his treatise De Utilitate Credendi, written around 391 to urge his friend Honoratus to return to the Catholic faith, he states^[12]:

"I call a miracle whatever is difficult or unusual and appears beyond the hope or the ability of the astonished witness." — Saint Augustine, De Utilitate Credendi, XVI, 34, c. 391^[13]

The Augustinian definition is broad: it emphasizes the subjective reaction of the witness — astonishment, admiration — rather than a precise ontological structure. It provisionally includes anything that exceeds the habits of a given observer, even if this event is objectively explicable to a more learned man. This broad definition will later be refined and tightened by Thomas Aquinas.

Miracle in the City of God

In the City of God (XXI, 8), Saint Augustine returns to the miracle in order to clarify its nature in relation to the natural order. He is the first to clearly formulate the distinction between what goes against nature (a corpse that does not decay) and what simply goes beyond the known natural order^[14].

"What we call contrary to nature is not contrary to nature in the absolute sense; it is contrary to nature as we know it." — Saint Augustine, De Civitate Dei, XXI, 8^[15]

This formula is of capital importance: it anticipates the Catholic response to Hume's objection of "violation of the laws of nature." For Augustine, God never acts against his own creation — he acts beyond the ordinary natural order, according to a higher and hidden law. Nature is God's habitual will; the miracle is his free will outside of habit.

Augustine also insists on the historical dimension of miracles. In the City of God, he devotes several books to the miracles that accompanied the growth of the Church in the Roman Empire — healings, conversions, inexplicable phenomena around the relics of the martyrs — and he carefully distinguishes true miracles from the illusions of demons^[16].

Contra naturam or praeter naturam?

The central distinction in Augustinian thought is that between contra naturam (against nature) and praeter naturam (outside the order of nature). Augustine clearly prefers the second formulation, since the miracle is not a denial of creation, but an act of God that transcends the laws he himself established^[17]. This nuance will prove decisive for Thomas Aquinas and, later, for the apologetic response to Hume.

Creation as a Perpetual Miracle

Beyond the isolated miracle, Saint Augustine develops an intuition that has remained famous: the ordinary government of creation is itself a perpetual miracle, greater than the spectacular miracles performed by Jesus. In his Tractatus in Iohannem 24, commenting on the multiplication of the loaves, he exclaims^[18]:

"The multiplication of the loaves, by which five thousand men were filled, is a miracle. Yet no one is astonished to see, every day and throughout the whole earth, grain multiplied from a few seeds. What was done for a few was meant to astonish; but what is done for all goes unadmired, not because it is lesser, but because it is usual." — Saint Augustine, Tractatus in Iohannem, 24, 1, c. 416–418^[19]

This thesis — taken up by Bossuet, Newman and later by Chesterton — radically shifts the perspective. The real question is not "why does God perform a few miracles?", but "how is it that all of nature, at every instant, is already the work of a power that sustains it in being?". The local miracle then appears as a break in routine: it reminds us, at a single point, that all of nature is suspended from a perpetual divine act. This line of thought will be central to Saint Thomas (creation as a continual act, creatio continua) and provides Catholic apologetics with a decisive answer to the rationalist objection: what would call for a miracle is not that there are sometimes miracles, but that there is something rather than nothing.

Miracle and Admiration: The Thomistic Definition

Saint Thomas Aquinas (1225–1274) takes up and systematically develops the Augustinian definition in the Summa Theologiae (Ia, q. 105, a. 7). His definition is more precise:

"The word miracle comes from the word admiration. Admiration arises when effects appear whose cause remains hidden. Thus admiration arises when one sees a solar eclipse and does not know its cause. Now the cause of an effect apparent to all may be known to some and unknown to others: thus an eclipse astonishes the ignorant man, but not the astronomer. But a miracle is an event that arouses full admiration because its cause is entirely hidden from all. And that cause is God. Hence the actions that God performs beyond the causes known to us are called miracles." — Saint Thomas Aquinas, Summa Theologiae, Ia, q. 105, a. 7, reply^[20]

The Thomistic precision is decisive: the cause of the miracle is entirely hidden from all, not merely from some ill-informed observer. A miracle is not a mere individual epistemological gap: it is a fact for which no created natural cause can account. The astronomer understands the eclipse; no one "understands" naturally how a man born blind instantly recovers his sight (Jn 9).

The Three Orders of Miracles

In the same article (Ia, q. 105, a. 8), Thomas establishes a tripartite classification of miracles according to the way in which they exceed natural power. This classification remained normative in Catholic theology until the twentieth century^[21]:

"Nothing can be called a miracle if it is referred to the divine power, because everything produced by God, compared to His power, is negligible. But an event is qualified as a miracle in comparison with the power of nature which it exceeds." — Saint Thomas Aquinas, Summa Theologiae, Ia, q. 105, a. 8, reply^[22]

This table reveals an important logic: the resurrection of the dead belongs to the second order, not the first, because nature can produce life — but not in a corpse already dead. The instant healing of a fever belongs to the third order — the least spectacular of the three — because it is an effect that nature can produce, but not in this manner (instantly, without remedy, at God's command). This gradation avoids demanding the same level of proof for every category.

Instrumental Causes: The Saints as Instruments of God

For Thomas Aquinas, the miracles worked by the saints do not come from any power of their own, but from God alone, who uses them as instruments^[23]. No one, saint or angel, can work a true miracle by his own strength, because a miracle by definition surpasses the order of all created nature. Saint Gregory the Great expresses it thus, as quoted by Thomas:

"The saints work miracles sometimes by authority (ex potestate), sometimes by prayer (ex prece). In both cases, God is the principal author, who uses instrumentally their interior movement, their word, or an outward act." — Saint Gregory the Great, Dialogues, II, 30, quoted by Saint Thomas, IIa-IIae, q. 178, a. 1^[24]

"By authority" does not mean here a power of one's own: Thomas explains that the saint then acts without any prior prayer expressed — as Peter before Ananias and Sapphira (Acts 5:4–9) — but always as an instrument moved by God, in the same way as a miracle obtained through prayer, such as Peter raising Tabitha (Acts 9:40).

This doctrine of instrumental causality is fundamental: it explains why the Church can recognize miracles attributed to saints or relics (for example, the resurrection of a dead man at the touch of Elisha's tomb, 2 Kgs 13:21), without claiming that these saints or objects possess any intrinsic supernatural power.

Vatican I, Dei Filius (1870): Miracles as Motives of Credibility

The First Vatican Council, in its dogmatic constitution Dei Filius (24 April 1870), deals with miracles within the framework of revelation and faith. It is the first systematic magisterial definition of the function of miracles in the economy of faith^[25]. The Council affirms:

"So that the homage of our faith might be in accordance with reason, God willed that the inner helps of the Holy Spirit be accompanied by the outer proofs of His Revelation. Thus the miracles of Christ and the saints, the prophecies, the propagation and holiness of the Church, her fruitfulness and stability are sure signs of Revelation, suited to the intelligence of all, motives of credibility which show that the assent of faith is by no means a blind movement of the mind." — First Vatican Council, Dei Filius, ch. 3, DS 3009 (1870)^[26]

The phrase "suited to the intelligence of all" is crucial: the miracle is not reserved for theologians or mystics. It is a public fact, perceptible and verifiable, that speaks to any rational being of good will. Vatican I presents miracles as a bridge between reason and faith — not a substitute for reason, but a sign that invites reason to open itself to the supernatural.

Here Vatican I responds directly to the rationalism prevalent in the nineteenth century, which denied the very possibility of miracles in the name of the laws of nature. The Council is not content merely to affirm that miracles took place; it affirms that they are possible, that they belong to the providential order of Revelation, and that denying them amounts to mutilating the meaning of God's relationship with His creation^[27].

The Catechism of the Catholic Church (1992)

The 1992 Catechism integrates the doctrine of miracles within a Christological and paschal perspective. It carefully distinguishes the function of the miracles of Jesus^[28]:

"Jesus accompanies his words with many miracles, prodigies and signs (cf. Acts 2:22) which manifest that the Kingdom is present in him. They attest that Jesus is the Messiah foretold." — Catechism of the Catholic Church, § 547^[29]

"The signs worked by Jesus testify that the Father has sent him. They invite belief in him. To those who turn to him in faith, he grants what they ask. So miracles strengthen faith in him who does his Father's works; they bear witness to him. Yet they can also be occasions of temptation. They are not intended to satisfy curiosity and the desire for magic." — Catechism of the Catholic Church, § 548^[30]

This formulation of the CCC highlights the inseparable link between miracle and faith: the miracle is not a mechanical demonstration of divine power that would impose itself on reason. It calls forth faith, strengthens it, but does not replace it. It can also become an "occasion of falling" — Jesus is accused by some of performing his miracles in the name of Beelzebul (Mk 3:22).

The Norms of the Dicastery for the Doctrine of the Faith (2024)

On 17 May 2024, the Dicastery for the Doctrine of the Faith issued new Norms for Proceeding in the Discernment of Alleged Supernatural Phenomena^[31], replacing the 1978 norms. These norms introduce several significant changes:

• The diocesan bishop remains the principal agent of discernment, but under closer oversight by the Dicastery.
• Six graduated conclusions are provided: Nihil obstat; Prae oculis habeatur; Curatur; Sub mandato; Prohibetur et obstruatur; Declaratio de non supernaturalitate. Even the nihil obstat, the most favourable, does not affirm the supernatural character of the phenomenon: it merely states that no obstacles to devotion are found and that positive spiritual fruits are discerned.
• The emphasis is placed on spiritual fruits as the primary criterion: conversions, return to the sacraments, increased prayer, reconciliation — more than on the verification of extraordinary facts alone.
• The risks of financial manipulation, doctrinal deviance or undue psychological influence must be explicitly assessed.

These norms illustrate the constant wisdom of the Church: the strong affirmation of the possibility of miracles goes hand in hand with a demanding methodology of verification.

The three complementary dimensions

The miracles of Jesus are the reference model for all Catholic theology of miracle. They simultaneously present the three biblical dimensions: they are signs (they reveal the messianic mission), wonders (they arouse the admiration of witnesses), and mighty works (they manifest divine omnipotence)^[32].

The fact is structural, not anecdotal: according to the order of magnitude put forward by Fr. Raniero Cantalamessa, about one third of the Synoptic Gospels is devoted to the healings and exorcisms performed by Jesus during his public life, to the point that it is impossible to give them a purely symbolic reading without undermining the very coherence of the gospel text^[33].

"The works that I do in my Father's name, they bear witness to me." — Jesus, John 10:25^[34]

The Gospel of John organizes its narrative around seven major signs, chosen for their symbolic and theological value: the turning of water into wine at Cana (John 2), the healing of a royal official's son (John 4), the healing of a paralytic (John 5), the multiplication of the loaves (John 6), the walking on the waters (John 6), the healing of a man born blind (John 9), and the raising of Lazarus (John 11)^[35]. This selection is not exhaustive — John states that "there are also many other signs" (John 20:30) — but it illustrates that the miracles were not chosen arbitrarily: they form a coherent discourse on the identity of Christ.

The rejection of the miracle as spectacle

The Gospel insists repeatedly that Jesus refuses the miracle as spectacle — the miracle demanded in order to test or compel faith. He rejects the temptation in the desert to throw himself from the Temple in order to be saved by the angels (Matt 4:5–7; Luke 4:9–12). He performs no miracles in Nazareth because of the inhabitants' unbelief (Mark 6:5–6). He is indignant with those who demand a sign from heaven in order to believe (Mark 8:11–12)^[36].

"An evil and adulterous generation asks for a sign; but no sign shall be given to it except the sign of Jonah." — Jesus, Matthew 16:4^[37]

This rejection is theologically consistent with the definition of the miracle as a sign: a sign does not impose its conclusion; it invites it. Faith remains a free act. The miracle, precisely because it is a sign and not a mechanical demonstration, can always be refused by one who does not want to see^[38].

The resurrection: the founding miracle

Beyond all the other miracles, the Resurrection of Christ is presented by the New Testament as the founding miracle of the Christian faith. Saint Paul expresses this unambiguously:

"If Christ has not been raised, our faith is in vain." — Saint Paul, 1 Corinthians 15:17^[39]

The Resurrection is not one miracle among others: it is the sign that gives meaning to all the others. It belongs to the first order of Thomistic miracles (supra naturam): nature cannot bring a dead man back to glorious life. It is also the foundation of the whole apostolic proclamation — the Acts of the Apostles makes the Resurrection the heart of the announcement (Acts 2:24; 3:15; 4:10; 10:40)^[40].

The rationalist presupposition: "the miracle cannot happen"

Before Hume, it was Baruch Spinoza (1632–1677) who laid down the classic rationalist lock. In his Theological-Political Treatise (1670), in chapter VI devoted to miracles, he defends a radical thesis^[41]:

"Nothing happens in nature that contradicts its universal laws; nothing either that does not accord with them, or that does not flow from them. […] A miracle, whether it contradicts nature or whether it cannot follow from it, is a sheer absurdity." — Baruch Spinoza, Tractatus Theologico-Politicus, ch. VI, 1670^[42]

For Spinoza, as later for Voltaire, d'Holbach, Renan, or Bultmann, the verdict is rendered a priori, before any inquiry: since nature is governed by necessary laws and God, if he exists, either is identical with those laws (Spinozist pantheism) or cannot deviate from them (deist rationalism), a miracle is by definition impossible. Every account of a miracle is therefore necessarily false: one must look behind it for a fraud, an illusion, a myth, a psychological projection, or a metaphor.

This point is central to understanding the debate: the classic rationalist does not refute miracles; he excludes them. He does not say "I have examined the best cases and they can be explained" — he says "whatever the strength of the testimony, the conclusion is known in advance." This is exactly what Joseph Ratzinger reproaches in Jesus of Nazareth when he criticises the historicist a priori that decides, before opening the Gospel, that the miracles could not have taken place^[43]. The most honest contemporary objection must therefore begin by admitting that it is metaphysical, not empirical: it is a decision about what the world can be, not a balance sheet of what has been observed in it.

Hume's argument

The Scottish philosopher David Hume (1711–1776) is the author of the most influential philosophical critique of the credibility of miracles. In Section X of his Enquiry Concerning Human Understanding (1748), he gives this definition^[44]:

"A miracle may be accurately defined, a transgression of a law of nature by a particular volition of the Deity, or by the interposition of some invisible agent." — David Hume, An Enquiry Concerning Human Understanding, Section X, 1748^[45]

His argument against the credibility of testimony to miracles is twofold. First, the evidence against a miracle is always maximal, since it rests on the uniform experience of nature: natural laws have been confirmed by millions of observations, whereas the miracle rests on a few testimonies. Second, human testimony is fallible and subject to bias (love of the marvelous, credulity, group interest)^[46]. Conclusion: the probability that the testimony is false is always greater than the probability that the miracle is real.

The limits of Hume's argument

Hume's argument rests on two fragile presuppositions, noted in particular by C. S. Lewis in his book Miracles (1947)^[47] and by contemporary philosophers such as Alvin Plantinga^[48].

First presupposition: experience is "uniform". But the uniformity of experience is itself established only if miracles are excluded a priori from the observational corpus. This is a begging of the question: one says that miracles are impossible because experience does not confirm them, but one has already excluded testimonies of miracles in the name of the impossibility of miracles.

"If God exists, miracles are not only possible; they are to be expected in certain contexts. To refuse to consider this possibility before even examining the testimonies is to let metaphysics decide before the inquiry." — C. S. Lewis, Miracles, ch. XIII, 1947, French trans.^[49]

Second presupposition: the miracle is a violation of the laws of nature. But the Thomistic formulation is more precise: God does not act against the laws he has created; he acts beyond the order of secondary causes. As Lewis writes in his famous example: if God miraculously brings about the conditions for a pregnancy outside the ordinary course, all the natural laws — biological, physiological, embryological — at once resume their rights. The miracle does not abolish nature; it transcends it at a given point^[50].

Third limit: Hume's argument proves too much. If multiple, concordant, verifiable testimonies of extraordinary facts were always to be set aside in favour of the hypothesis of error, one would also have to doubt many rare historical or medical facts that Hume himself accepted without difficulty^[51].

The positive theological response

The Catholic response is not merely defensive. It positively affirms that miracles are knowable through a threefold criterion: rigorous verification of the fact, methodical exclusion of known natural causes, and discernment of the religious sign it bears. The Church has never asked for blind belief: it has established procedures of inquiry (Lambertini in the eighteenth century, the Lourdes Medical Bureau since 1883, the new DDF norms of 2024) precisely to distinguish the authentic miracle from any simulation, illusion, or unknown natural explanation^[52].

The confusion of these three levels is the source of most practical errors, whether in the direction of credulity or of scepticism^[53] :

The astonishing

An event is astonishing as soon as it departs from the ordinary course of things or surprises the observer. A rapid recovery from cancer after intensive chemotherapy may be astonishing — and arouse sincere gratitude — without being miraculous in the strict sense. Human nature is surprising; the body, under certain circumstances, may exceed our usual medical prognoses. The astonishing does not prove the supernatural.

The unexplained

An event is unexplained when current medical, scientific, or historical means cannot account for it. Inexplicability is always provisional: a disease unexplained today may receive its explanation tomorrow as knowledge advances. This is why the Lourdes Medical Bureau carefully speaks of "a healing currently unexplained in the present state of medical knowledge"^[54] — a deliberately open-ended formula, which does not prejudge the future.

"The absence of a scientific explanation is not the affirmation of the supernatural. It is the observation of a gap — perhaps a provisional one — in our knowledge." — Lourdes Medical Bureau Form, official recognition procedure^[55]

A recent example illustrates this methodological prudence well. Between 1996 and 1998, in Mourão, Portugal, thousands of the faithful believed they saw the face of Christ forming on an exposed host. The Archdiocese of Évora opened a scientific investigation: experts established that the phenomenon resulted from an effect of the refraction of light on figures embedded in the monstrance itself^[56]. The episode discredits neither the piety of the witnesses nor the legitimacy of the investigation; on the contrary, it shows that the correct Catholic reflex before the unexplained is neither sceptical denial nor hasty proclamation, but patient expertise.

The miraculous in the proper sense

"What, in fact, is the miracle properly so called? It is a fact accomplished outside the laws of all created nature; a fact that God alone can produce, and that clearly shows the free and extraordinary intervention of divine omnipotence; a fact which, by its very nature, is a most certain sign, accommodated to every intelligence, of the divine origin of the revealed doctrine in whose favour it bears witness." — Réginald Garrigou-Lagrange and Benoît-Marie Lavaud, "Les circonstances de la stigmatisation", Études carmélitaines, mystiques et missionnaires, October 1936^[57]

An event is miraculous in the proper sense when it fulfils several conditions^[58] : (1) the fact is solidly established and the testimonies are reliable; (2) known natural causes, including the rarest, have been seriously excluded; (3) the event displays the characteristics of a divine intervention: suddenness, completeness, durability, coherence with prayer, a context of faith; (4) the event carries a coherent religious meaning — it calls to faith, to conversion, to the acknowledgment of God; (5) the competent bishop and/or the Dicastery for the Doctrine of the Faith recognise its supernatural character. It is for the Church, at the conclusion of a rigorous inquiry, to render this judgment — not the doctor, nor the journalist, nor the enthusiastic believer.

The supernatural is not always the miraculous

One final, finer distinction completes this triptych. Not everything that is supernatural is necessarily miraculous in the technical sense defined above — and yet it may constitute, for the Church, an authentic sign worthy of consideration:

"[One must] distinguish between miracle and supernatural, the latter not being necessarily miraculous and yet being capable of constituting a sign." — Joachim Bouflet, Une histoire des miracles, Seuil, 2008, p. 296^[59]

Two concrete cases shed light on this nuance. On 13 October 1917, some 70,000 people gathered at Fatima witness the solar phenomenon that became famous as the "miracle of the sun"; yet this phenomenon, as such, has never been the subject of a formal canonical judgment that would legally qualify it as a miracle — without this detracting in any way from its force as a collective sign, acknowledged throughout the Fatima dossier^[60]. In Syracuse, Sicily, a statuette of the Virgin weeps tears from 29 August to 1 September 1953; the diocesan investigation concludes with certainty that the fact of the shedding of tears cannot be doubted^[61], but Bishop Ettore Baranzini immediately adds: "It is the nature of the miracle to be exceptional, and it must be seriously verified"^[62] — an authenticated material fact therefore does not automatically entail, case by case, the canonical qualification of each healing subsequently attributed to it.

Two Christian emphases: East and West

Before becoming a procedure, the miracle was first received differently by the two great Christian traditions. The Greek and Syrian Fathers see in it above all the radiance of a presence: the miracle is not an accident in the laws of nature, but the manifestation of God among humanity^[63].

« According to the Fathers, the miracle can only be conceived as the radiance of God's epiphany among humanity. Far from being an accident of the laws of nature, it shows the personal and powerful presence of God among us. » — Razvan Andrei Ionescu, art. « Miracle (chez les Pères grecs et syriaques) »^[64]

This Eastern sensibility culminates in a spiritual conviction that joins, further on in this article, the warning of Saint Francis of Assisi and Saint John of the Cross against attachment to the prodigy: the greatest Christian miracle is not the spectacular sign, but the conversion of the heart^[65].

The Latin West, while never denying this dimension of presence, develops from the early Middle Ages a distinct concern: that of proof. Three questions gradually overlap here — did a fact occur? does it stem from a known natural cause? does it carry a religious meaning clear enough to engage the judgment of the Church? It is this typically Latin probatory requirement that gives rise to the long institutional history recounted below.

Institutional milestones before Lambertini

As early as 993, Pope John XV canonises Ulrich of Augsburg: Joachim Bouflet sees in it the first milestone of a papal procedure destined to develop over several centuries, and the lasting inscription of the post mortem miracle of intercession within a canonical framework^[72]. A century later, under the pontificate of Urban II, the Church lays down a requirement that governs all that follows: no miracle may be accepted for inscription in the canon of saints without the direct testimony of someone who saw it with their own eyes^[73]. This eyewitness rule, several centuries prior to any modern medical expertise, shows that the requirement of proof is not a refinement of the nineteenth century: it is constitutive of the Catholic approach since the eleventh century.

The Council of Trent, in its session XXV of 3–4 December 1563, tightens control further: in cases of doubt or abuse concerning an alleged miracle, the local bishop must consult the metropolitan and the bishops of his province, and no new decision may be taken without referring the matter to the Roman pontiff^[74]. The decisive step is taken in 1588: the constitution Immensa aeterni Dei of Sixtus V introduces for the first time, in a systematic way, the three pillars of any modern investigation — the questioning of qualified witnesses, the methodical critique of testimony, and the request for a medical opinion^[75]. This last point is crucial: the medical expertise of a healing fact thus precedes the opening of the Lourdes Medical Bureau by nearly three centuries.

The episode of the Holy Thorn, in 1656, illustrates this procedure concretely even before Lambertini. On 24 March, Marguerite Périer, niece of Blaise Pascal and a boarder at the Abbey of Port-Royal, is declared cured of a chronic lacrimal fistula after contact with a relic of the Crown of Thorns. Two renowned surgeons examine her: Guillard, surgeon to Anne of Austria, at first incredulous, and Félix, the king's first surgeon; both attest to the disappearance of the fistula^[76]. The episode would nourish Pascal's reflection on the apologetic function of the miracle, in a climate marked by the Jansenist controversy — and it demonstrates, more than a century before Lourdes, that the medical investigation and the theological debate over an alleged miracle naturally go hand in hand in the Catholic tradition.

Lambertini's seven historical criteria

The academic criteria for a miraculous cure were systematised by Cardinal Prospero Lambertini (1675–1758), future Pope Benedict XIV, in his monumental treatise De Servorum Dei Beatificatione et Beatorum Canonizatione (1734–1738)^[77]. This treatise, the fruit of long practice in beatification and canonisation trials, sets out seven cumulative conditions for recognising a cure as miraculous^[78] :

1. The illness must be serious and difficult, if not impossible, to cure by ordinary means.
2. It must not have reached its terminal stage, where spontaneous improvement would remain plausible.
3. No effective treatment has been used, or the one used cannot explain the cure.
4. The cure must be sudden and instantaneous.
5. It must be perfect: the eradicated illness must not manifest itself again.
6. It must not have been preceded by a crisis or notable evacuation that would herald it by natural means.
7. No relapse must occur over time.

« The cure must be sudden and instantaneous [...] the eradicated illness must not manifest itself again. » — Criteria of Lambertini, cited by Joachim Bouflet, Une histoire des miracles, Seuil, 2008, p. 189^[79]

These seven criteria, in force since the eighteenth century in canonical procedure, remain the basis on which the Church's present practice rests. They have not been replaced but reformulated in contemporary medical language by the Lourdes Medical Bureau and the CMIL — suddenness, completeness, durability, absence of causal treatment, absence of convalescence — each of which, under different terminology, restates one of the seven Lambertinian requirements (see table below).

Miracle and holiness: the order of proofs

Why does the Church require such an abundance of precautions? Because the miracle is never, in a cause of canonisation, a self-sufficient proof: it comes to confirm a holiness already established by other means, never to replace it.

« They are like a divine seal confirming the holiness of a servant of God whose intercession has been invoked. » — John Paul II, « Les miracles sont des messages et signes d'un Dieu qui est Amour », L'Osservatore romano, 26 December 1987^[80]

Bouflet sums up the underlying logic: the holy wonder-worker is not holy because he heals; he heals because he is united to God^[81]. A post mortem miracle of intercession counts as a sign of holiness only after the prior examination of the heroic virtues of the Servant of God — never before, never in their place.

This hierarchy also explains why certain extraordinary phenomena, even spectacular ones, do not count as canonical miracles in a beatification cause. The stigmata are the clearest example:

« On ne juge pas de la sainteté d'un sujet par sa stigmatisation, mais bien plutôt de sa stigmatisation par sa sainteté, ou ses œuvres de sainteté [...]. » — Pierre Adnès, art. « Stigmates », Dictionnaire de spiritualité^[82]

The same applies to levitation, a preternatural phenomenon that long fascinated hagiographers without ever entering the list of admissible evidence: Herbert Thurston's classic study catalogued more than two hundred alleged cases of levitation, but judged the evidence serious for only a third of them — and pointed out that, whatever their documentary solidity, these cases cannot in any event be counted among the miracles required for a beatification or a canonization^[83]. Stigmata, levitation, ecstasies, odours of sanctity: these phenomena belong to the preternatural — what exceeds the powers of man without exceeding those of any created nature — and not to the miraculous in the strict sense, which alone enters the evidentiary file of a canonization cause^[84].

The double examination: from the consulta medica to the 1983 norms

The procedure for the recognition of miracles in canonization causes underwent one last major overhaul in the twentieth century. On 28 October 1946, Pius XII created the consulta medica, a permanent college of medical experts charged with examining the healings alleged in beatification and canonization trials — thereby establishing a structural double examination, medical then theological, of every extraordinary fact submitted to Rome^[85]. Paul VI reorganized the competent dicasteries in 1969, and John Paul II in turn specified the rules of procedure in 1983, within the framework of the new legislation on the causes of saints^[86]. This double examination — a medical college that attests inexplicability, a theological commission that discerns sign-value — would remain the model on which, a few decades later, the system specific to Lourdes would be aligned.

The Lourdes Medical Bureau

It all begins with an episcopal mandate. On 18 January 1862, Mgr Bertrand-Sévère Laurence, Bishop of Tarbes, officially recognised the authenticity of the apparitions at the Grotte of Massabielle; his decision rested in part on the healings already verified: “The apparition is divine, since the healings bear a divine hallmark”^[87]. Out of nearly forty healings alleged in the early years, twenty-nine files were submitted to an inquiry commission; Canon Henri Vergez, charged with the investigation, initially retained only nine, and then seven, as sufficiently documented to support the episcopal judgment^[88]. This rigorous sorting, from the very start, belies the image of complaisant recognition: of twenty-nine cases submitted, fewer than a quarter passed the first filter.

Founded in 1883 by Dr Georges-Fernand Dunot de Saint-Maclou at the request of Father Rémi Sempé, the Lourdes Office of Medical Observations (Bureau des constatations médicales) is the world's first body for the collegial medical assessment of supposedly miraculous healings^[89]. Its formation was in fact gradual: medical certificates were required from 1880, an observation pavilion was built in 1884, and the Bureau took up permanent quarters under the arcades of the Rosary in 1893^[90]. Saint-Maclou was keen to open it to any doctor present on site, whatever his religious convictions — a protocol of independence that remains the Bureau's hallmark to this day^[91].

Institutional prudence grew even stronger under Pius X. In 1904, the Pope warned Dr Boissarie, then president of the Bureau: “The word 'miracle' must not be pronounced lightly”^[92]. From November 1905 onwards, the Lourdes healings were submitted to genuine diocesan canonical trials, the bishop of the healed person's place of origin becoming solely competent for official recognition — a principle already laid down by Trent in 1563 and which Lourdes now put into practice systematically^[93]. The interwar period illustrates the lasting severity of this filter: 609 files were opened, and only 228 healings were retained as certain, definitive and inexplicable — without all of them thereby receiving a canonical proclamation of miracle. Dr Vallet then set out the division of roles that has since become classic: for doctors to determine whether a person passed instantaneously from a state of sickness to a state of health, without medication, without convalescence; for theologians to assess whether this change bears a miraculous character or not^[94].

It has received more than 7,300 reported cases since 1858; of this total, 72 healings have been officially recognised as miracles by the Church, the 72nd having been proclaimed on 16 April 2025^[95]. In 2008, at the time Bouflet published his investigation, the count stood at about a thousand healings alleged since 1946, only some thirty declared unexplained by the CMIL, and twenty-seven proclaimed miraculous out of sixty-seven miracles recognised in total since the sanctuary's origins — figures that measure, at every historical stage, the extent of the selection rather than any ease of recognition^[96].

The current process comprises three stages^[97]:

1. Examination by the Lourdes Office of Medical Observations: presentation of the complete medical documentation; examination by a group of volunteer doctors of all nationalities and religions; conclusion on the “currently inexplicable” character.
2. Referral to the Lourdes International Medical Committee (CMIL): created in 1947 and internationalised in 1954, it studies the retained cases and delivers an opinion on medical inexplicability by a qualified majority vote (2/3); since 1975, it may also reopen and re-examine earlier conclusions in the light of new medical knowledge^[98].
3. Diocesan investigation and the bishop's ruling: the medical file is transmitted to the diocese of the healed person's origin. A diocesan commission, bringing together theologians and doctors, examines the religious sign and the absence of natural causes. The bishop pronounces or does not pronounce official recognition.

This process takes an average of ten to fifteen years^[99]. It illustrates the epistemological rigour of the Church: neither haste, nor a priori refusal. A sign of this enduring prudence, an intermediate pastoral category was even discussed in 2006-2007: several people who had benefited from a healing judged inexplicable, without their file having passed every stage of canonical recognition, were invited to bear local witness to an “inexplicable healing grace” — without this testimony being equivalent to the proclamation of a miracle in the full sense^[100].

The approach of the Emmanuel Community and the contemporary ministry of prayer for healing

Alongside the long canonical circuit (Lambertini → Lourdes Medical Bureau → CMIL → bishop), the second half of the twentieth century saw the development within the Catholic Church of a more ordinary ministry of prayer for healing, particularly carried by the Emmanuel Community (founded in Paris in 1972 by Pierre Goursat and Martine Laffitte-Catta), by the Catholic Charismatic Renewal in general, as well as by religious orders such as the Béatitudes, Verbe de Vie or Chemin Neuf^[101].

This ordinary ministry must not, however, be confused, theologically, with the canonically recognised miracle described above. In 2000, the Congregation for the Doctrine of the Faith recalled this unambiguously:

« Le "charisme de guérison" [...] ne fait pas partie de ces phénomènes thaumaturgiques. » — Joseph Ratzinger and Tarcisio Bertone, Instruction on Prayers for Healing, Congregation for the Doctrine of the Faith, 14 September 2000, § 5^[102]

In other words, a healing grace received in prayer — however real, however overwhelming for the person concerned — is not in itself equivalent to a miracle in the canonical sense defined above, and is not meant to undergo the same procedure of public authentication. This is why those responsible for this ministry insist on the need never to announce a healing prematurely as miraculous:

"Do not be tempted to see a miracle where there is no miracle." — Bishop Talamas, quoted by René Laurentin, Miracle à El Paso ?, Desclée de Brouwer, 1981^[103]

One must verify how long the healing lasts over time, rule out any later relapse, and remember that the healing of the heart is always worth more than physical healing alone^[104].

The constant teaching of the Emmanuel Community — visible in the annual Charisma sessions in Paray-le-Monial and in the Béthanie service accompanying people in suffering — comes down to a few simple rules, fully in line with Catholic doctrine:

• God can still heal today, and he does: physical healings, inner healings (wounded memories), spiritual liberations. To refuse this out of hand is to give in to modern rationalism. Pierre Goursat never stopped reminding people: "Christ is the same yesterday, today, and forever."^[105]
• A miracle is never owed: no technique, no intensity of prayer, no human holiness can compel God. The ministry of prayer asks; it does not wrest.
• True healing always leads to conversion, not to the satisfaction of a need. A return to the Eucharist, a family reconciliation, a liberation from sin is worth more than an isolated bodily healing.
• Discernment is mandatory: all prayer for healing takes place within ecclesial communion, never in absolute privacy, never against medical advice, never in competition with the sacraments. Any extraordinary phenomenon reported is submitted to the discernment of the reference priest and, where applicable, to the bishop.

This pastoral practice reconciles, without confusing them, the trusting prayer of the Gospel (Mt 7:7; Mk 11:24; Jas 5:14-15) and the rigor of investigation inherited from Lambertini. It shows that, in the ordinary life of the Church, the miracle is not a rare oddity reserved for Lourdes: it is the hoped-for horizon of a faith that asks God for what he has promised, without confusing the promise with a contract.

Criteria for a "medically inexplicable" healing

For a healing to be judged "medically inexplicable" by the Bureau, it must meet all of the following conditions^[106]:

These criteria clearly show that the Catholic approach does not demand the impossible: it does not claim that the physician proves the miracle, but that he attests to its inexplicability given the current state of science. The judgment of its supernatural character belongs to the Church.

Beyond healings: technical miracles

Not all canonization causes concern bodily healings. Multiplication of a food, an unexplained preservation of an object or place, a physical inexplicable phenomenon: these rarer cases require a different kind of expertise. As Michele Di Ruberto, for many years secretary-general of the Congregation for the Causes of Saints, recalls:

"The examination does not fall to physicians, but to a panel of technical experts." — Michele Di Ruberto, "La necessità dei miracoli", 30 Giorni nella Chiesa e nel mondo, March 2004^[107]

Depending on the exact nature of the alleged event, this panel of experts may include engineers, chemists, physicists, or art restorers — the underlying logic remaining identical to that of the Lourdes Medical Bureau: to rigorously establish the inexplicability of the fact given the current state of knowledge, before the Church pronounces on its value as a sign.

Pellevoisin: a model of double investigation

The Marian apparition at Pellevoisin (1876), received by Estelle Faguette, offers a particularly clear example of this two-stage logic — medical finding, then distinct theological discernment. The medical reports conclude that Estelle's healing was:

"sudden, that is, without convalescence, complete, lasting." — Medical reports cited in the decree of Archbishop Paul Vignancour of Bourges, 8 September 1983^[108]

But this medical finding alone is not enough to qualify the event as a religious miracle. The diocesan theological commission must examine separately:

"the sign value of this healing." — Decree of Archbishop Paul Vignancour, 8 September 1983^[109]

This doubling — medical inexplicability on one side, religious meaning on the other — is precisely the structure that Sixtus V had sketched out in 1588 and that Lourdes would systematize on a larger scale: no healing, however spectacular, is automatically a miracle as long as the Church has not discerned its meaning.

The two symmetrical pitfalls to avoid

The Catholic attitude toward miracles is demanding precisely because it refuses the two easy paths. These pitfalls must be named, for they mirror each other like two distorting mirrors^[110]:

The Church refuses both paths: credulity because it dishonours truth, rationalism because it stifles God's freedom. This is why Catholic discernment demands both great faith and thorough investigation — not as a lukewarm compromise, but as the twofold requirement of a single love of truth.

Neither credulity nor scepticism

The Catholic tradition simultaneously upholds two positions that may seem to be in tension: on the one hand, the possibility and reality of miracles — the Church firmly believes that God still acts in history through extraordinary interventions, and rejects any rationalism that would deny a priori the supernatural^[111]; on the other hand, a rigorous method of investigation that yields neither to immediate enthusiasm, nor to popular credulity, nor to the exploitation of the faithful^[112].

This double balance is itself doctrinal. Denying miracles means denying God's omnipotence over His creation. But too readily crediting any extraordinary account means exposing the faithful to illusions, to manipulation, and to a fragile faith founded on emotion rather than on truth. The father in the Gospel expresses this tension perfectly when he says to Christ: "I believe, Lord, come to the help of my little faith!" (Mk 9:24)^[113].

Miracles do not override freedom

A constant principle in the Church's teaching: miracles invite faith; they do not compel it. This principle follows directly from God's respect for human freedom. Jesus Himself, despite miracles "so evident", is rejected by some and accused by others of acting through demons (Mk 3:22)^[114]. The miracle is an invitation, a call, a sign — never a proof that would impose itself mechanically upon the mind^[115].

« Je ne vous oblige pas à croire à mes manifestations de miséricorde à force de miracles. Même durant ma vie mortelle — tu le lis dans l'Évangile — la condition pour obtenir mes grâces était toujours la même : "Peux-tu croire ? À celui qui croit, tout est possible !" » — Jésus à la vénérable sœur Consolata Betrone (1903-1946), Jésus parle au monde, Éditions Parvis, 1994, p. 22^[116]

Miracles and the spiritual life

In the Catholic mystical tradition, miracles — even those wrought by the saints — are not the summit of the spiritual life. The great spiritual masters warn against excessive attachment to extraordinary phenomena. Saint Francis of Assise warns in his Admonitions^[117]:

« Serais-tu le plus beau et le plus riche des hommes, et ferais-tu même des miracles au point de chasser les démons, tout cela peut se retourner contre toi. Ce dont nous pouvons tirer gloire, c'est de nos faiblesses. C'est de notre part quotidienne à la sainte Croix de notre Seigneur Jésus-Christ. » — Saint François d'Assise, Admonitions, 5, 5-8^[118]

Saint John of the Cross recalls that the soul must not rely on extraordinary graces — visions, locutions, miracles — but on naked faith and the cross^[119]. The miracle is a sign for non-believers or for moments of special grace; it is not the ordinary regime of the Christian life, which is lived out in humble faith, concrete charity, and perseverance in trials.

• The miracles of Lourdes — 72 recognized healings, the Medical Bureau, scientific and canonical criteria.
• Miraculous healings — a detailed study of medical criteria and ecclesial discernment.
• Eucharistic miracles — hub of miracles associated with the Eucharist (Lanciano, Bolsena, Buenos Aires, Sokolka).
• The discernment of supernatural phenomena — the DDF's new norms (2024).
• The miracle of the sun (Fatima, 1917) — an analysis of a public and collective miracle.
• Miracles in other religions — comparison and discernment.
• Cosmological fine-tuning — the argument from the fine-tuning of the universe.
• The resurrection of Jesus — the founding miracle of the Christian faith.