Light phenomena

Six forms, one and the same biblical root

Catholic hagiographical literature groups under the word "luminous" observations of very different kinds, which the method requires us to separate before any evaluation. The chapter Joachim Bouflet devotes to the subject allows six recurring forms to be identified^[4]:

1. the halo or facial nimbus perceived during prayer or the celebration of Mass;
2. the globes of fire, stars or sparks emitted by the body, especially the mouth;
3. the light at the moment of death, observed in the dying person's room;
4. the post-mortem light associated with the body or the tomb, sometimes months or years after death;
5. the light emanating from a consecrated host, particularly during acts of sacrilegious theft;
6. the light on a holy image or statue.

These six forms share one and the same matrix: the biblical language of divine glory, from the transfigured face of Moses to the Transfiguration of Christ, which the next section develops. But the symbolic matrix dispenses us from no concrete question — who saw, for how long, at what distance, with what source of ambient lighting, and with what spiritual fruits.

What this article covers, and what it leaves to other files

The phenomenon most often confused with light is mystical heat — the incendium amoris that mystics say they have felt in the chest, sometimes with effects verified by third parties (scorched clothing, wildly reading thermometers). One and the same testimony frequently employs both registers at once: a face said to be "radiant" may, on examination, be no more than a sign of hyperthermia or vasodilation. This file is treated on its own terms in L'incendium amoris, and this article returns to it only to point out cases where the two phenomena are intermingled in one and the same source.

Likewise, the odour of sanctity belongs to yet another chapter of Bouflet's encyclopedia, and the preservation of the body after death — mummification, corification, saponification — falls within the separate file treated in Les corps incorruptibles. The neighbouring phenomena of stigmatisation, levitation and inedia each have their own article^[5]. This article focuses on bodily luminosity properly so called: what a witness says they saw, not what they felt or touched.

The Face of Moses, Reflecting a Glory That Is Not His Own

Moses comes down from Sinai, the Tablets of the Law in his hands. The Book of Exodus describes a light that Moses himself does not notice:

"he did not know that his face shone with light since he had spoken with the Lord." — Exodus 34:29, AELF liturgical translation^[6]

Aaron and the children of Israel see this radiance and at first dare not come near. Moses passes on the words he has received, then covers his face with a veil (Ex 34:30–35). The text thus distinguishes the experience of the servant of God from what those around him are able to see.

The Transfiguration, a Foreshadowing of Glorified Bodies

On Mount Tabor, Christ manifests his glory before Peter, James, and John:

"his face shone like the sun, and his garments became white as light." — Matthew 17:2, AELF liturgical translation^[7]

The Thomistic tradition counts brightness among the four qualities of the glorified body, together with impassibility, subtlety, and agility. The Supplement of the Summa Theologiae treats these qualities in questions 82 to 85; question 85, article 1, relates the brightness of the body to the overflowing of the soul's glory^[8].

This framework gives meaning to the Christian image of the luminous body: salvation concerns the whole person, soul and body. It does not turn every account of light into a demonstrated anticipation of the resurrection; applying it to a historical case requires that the observation and its context be examined.

In his summary of Benedict XIV, Adolphe Tanquerey asks us to establish whether the observation takes place in broad daylight or at night, and whether the light, beyond its duration, recurs several times. Among the spiritual fruits, he names lasting conversions. He makes the conclusion as to the supernatural character dependent on the examination of all these elements, together with the religious context and the virtue of the person^[9].

Establish the Fact Before Seeking Its Cause

Before even presenting the first case, Bouflet summarizes the five criteria of Prospero Lambertini — canon lawyer, promoter of the faith, then pope under the name Benedict XIV (1740–1758) — in his reference treatise on canonization processes:

"1. It is brighter than the surrounding lights. 2. It is not fleeting like a flash of lightning, but lasts for a certain time. 3. It manifests itself in a context of prayer, or when God, spiritual matters, are being discussed. 4. The person concerned must show at least signs of uncommon virtues. 5. The phenomenon must produce spiritual fruits in the witnesses." — Joachim Bouflet, summarizing Prospero Lambertini, Encyclopédie des phénomènes extraordinaires dans la vie mystique, vol. 1, Le Jardin des Livres, 2015, p. 67^[10]

Adolphe Tanquerey, who likewise summarizes Benedict XIV, begins with a material requirement:

"Above all, the fact must be carefully studied in all its circumstances, to see whether the light cannot be explained naturally." — Adolphe Tanquerey, Phénomènes mystiques extraordinaires, Sainte Jeanne d'Arc, 1986, p. 31^[11]

These five criteria structure the whole of the rest of Bouflet's chapter, and this article takes them up as a reading grid for each case presented below: comparative intensity, duration, context, virtue of the subject, fruits in the witnesses. Bouflet himself adds a decisive methodological caveat, concerning the case of Saint Colette of Corbie, one of whose biographers acknowledges that certain accounts of luminosity stem from the "imaginations" of her devout entourage:

"Only the Catholic Church, thanks in particular to its beatification procedure, possesses documentation on the luminosity of mystics that is usable by the historian." — Olivier Leroy, cited by Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, vol. 1, Le Jardin des Livres, 2015, p. 68^[12]

The Modern Criteria: Contradictory Witnesses and Control of Lighting

Three centuries after Lambertini, the essayist Aimé Michel adds requirements that modern historical investigation can apply retrospectively to old files. He first lays down a principle of method before examining any prodigy:

"Must one then believe in these prodigies that have all the historical criteria in their favour? I propose provisionally that, here as in other matters equally troubling, 'one be attentive to everything and believe in nothing.' Let us first see what the witnesses say. We shall then examine what criticism can be made of their testimonies." — Aimé Michel, Métanoia — Phénomènes physiques du mysticisme, Albin Michel, 1986, p. 112^[13]

He then specifies the standard of proof he expects of an extraordinary testimony, with a requirement of internal contradiction within the file:

"The testimony will be worth what the witness is worth; we want witnesses who are hard to deceive. [...] If it is a question of stigmata, I want a doctor, a biologist, I want several, of opposing opinions, having if possible an interest in asserting that the prodigy did not take place." — Aimé Michel, Métanoia — Phénomènes physiques du mysticisme, Albin Michel, 1986, p. 148–149^[14]

Transposed to light, this standard demands: independent witnesses, ideally initially sceptical; identified ambient lighting and, if possible, a comparison (switching an electric lamp back on to see whether the effect persists); a measurable duration; an effect visible in the environment, not merely on the subject's face. Michel adds one last principle, useful in the face of facts that are rare and by nature non-reproducible: a phenomenon may escape direct experimentation while leaving observable side effects — "they will trigger effects which, for their part, will fall under determinism, and thus under science"^[15]. Refusing by principle any fact known only through testimony amounts, he warns, to forbidding oneself from ever being warned of one's error^[16].

Pier Giorgio Frassati: "amounts to pious fiction"

The most common trap in this dossier lies in the vocabulary itself. Words such as radiant, resplendent, luminous or glowing belong to the standard register of hagiographic praise: they can describe beauty of features, serenity or complexion, without designating a light physically observed. Bouflet provides a precise example of this confusion, regarding the 1981 exhumation of Pier Giorgio Frassati, canonised on 7 September 2025^[17], whose account by Father Daniel Ange multiplied devotional formulas:

"The account of Father Daniel Ange should be stripped of its dithyrambic metaphors: the prodigy of incorruption [...] speaks for itself. The radiance of the face, the resplendence of the body and the delicate fragrance [...] amount to pious fiction." — Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, tome 1, Le Jardin des Livres, 2015, p. 400^[18]

Bouflet does not deny the fact of incorruption itself, which he considers remarkable in its own right; he merely refuses that the luminous vocabulary accompanying it in Father Daniel Ange's account be treated as an observation. The rule that follows for the rest of this article is simple: whenever a testimony uses a word from the "light" family, one must look for a localised source, a duration, an effect on the surroundings, a comparison with the ambient lighting and a plurality of independent witnesses — failing which the word documents only beauty or serenity.

Mary Magdalene de' Pazzi: radiant face, shining eyes, but no lit room

The same guardrail applies to an older documented case, that of Saint Mary Magdalene de' Pazzi (1566–1607), a Florentine Carmelite whose ecstasies are described by her biographer, Father Virgilio Cepari. Aimé Michel quotes this passage:

"Her face instantly lost the pallor caused by penances and the austere religious life and suddenly became radiant and glowing, her eyes shone like stars and she began to cry out." — Aimé Michel, Métanoia — Phénomènes physiques du mysticisme, Albin Michel, 1986, p. 113, quoting Virgilio Cepari^[19]

This passage does not claim that the face lit up the cell, cast a shadow, or remained visible in the dark: the text combines a shine in the eyes, a flushing of the complexion and an exceptional body temperature, without evidence of any independent light emission. Michel describes a heat "that radiated like that of a stove", felt by those around her^[20] — a phenomenon belonging to the family of the incendium amoris, not of light, and falling within the dossier on mystical heat. A comparable case, that of the Neapolitan Carmelite Serafina of God (d. 1699), combines in a single testimony a "face radiant as a flame", "sparkling eyes" and a heat such that the nuns who touched her were burned; this passage describes no luminous effect on the surroundings^[21].

Alexia González Barros: skin "almost glowing"

The third, later example confirms the rule. After the death of the Spanish teenager Alexia González Barros (1971–1985), her biography describes her face as follows:

"Alexia's face had taken on an unusual beauty. With her grave and peaceful air, she did not seem dead, but asleep. Her skin was white, almost glowing, her cheeks had a soft rosy colour." — Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, tome 1, Le Jardin des Livres, 2015, p. 451, quoting Pedro Antonio de Urbina, Alexia — Un sourire pour Dieu, Éd. Le Laurier, 1996, p. 263^[22]

The text mentions neither a light source, nor a halo, nor any abnormal lighting. It describes a whiteness of skin and a rosy colour of the cheeks — a typical case of post-mortem aesthetic transfiguration, not to be confused with an optical phenomenon. These three examples establish the method applied in the rest of the article: only the following cases, where a witness explicitly describes an effect on the surroundings, a duration or a comparison with a known light source, are retained as positive cases of luminosity.

Vincenzo Pallotti: a passer-by who did not know the priest

The first type of positive case is the halo or nimbus perceived above the head during prayer or the Eucharistic celebration. Vincenzo Pallotti (1795–1850), founder of the Society of the Catholic Apostolate and canonized in 1963, provides a documented example at two levels of testimony. A faithful woman, Elisabetta Sanna, reports having seen him "twice, while Don Vincenzo was celebrating Mass [...] his head haloed with a vivid light"^[23]. The second testimony is even more significant, since it comes from a passer-by who did not know the priest:

"The priest's head was distinctly surrounded by a halo resembling a bright burst of sunlight." — Giuseppe Giorgio, outside witness, Via Tor di Nona, Rome, 1848, cited in Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, vol. 1, Le Jardin des Livres, 2015, p. 70, citing F. Amoroso, San Vincenzo Pallotti, Rome, Postulazione, 1962, p. 399^[24]

Giuseppe Giorgio states that he did not know Pallotti: after passing him, he asked in a shop who this priest was. This circumstance sets his account apart from that of Elisabetta Sanna, who was already familiar with Pallotti, without making it possible to conclude that the passer-by held no religious conviction whatsoever^[25].

Brother André Bessette: the test of electric light

One case accompanied by a check of the lighting concerns Saint André Bessette, known as Brother André (1845–1937), doorkeeper of Notre-Dame College in Montreal and founder of Saint Joseph's Oratory, canonized on 17 October 2010^[26]. A witness, Adélard Favre, testifies during the beatification process:

"I saw, above Brother André's head, a source of light some 15 to 20 feet in circumference [...] this (luminous) phenomenon lasted from 3 to 4 minutes." — Adélard Favre, Summarium, pp. 331–332, nos. 77–80, cited in Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, vol. 1, Le Jardin des Livres, 2015, p. 71^[27]

Favre wanted to put an explanation by the sanctuary's lighting to the test. After telling Brother Ludger about his vision, he asked him to switch on the electric lights: the comparison did not reproduce the observed effect. Ludger appears here in the subsequent check, without being presented as a witness to the original brightness. This test answers a concrete question — is the usual lighting sufficient? — but it does not constitute a measurement of the intensity of the reported light^[28].

Jean-Michel Roy: a nimbus estimated at fifteen or twenty centimetres

On 8 May 1923, around 11:30 a.m., at the Church of the Miracles in Rome, Father Jules Saubat is alerted by the rector, and then observes Father Jean-Michel Roy, a religious of Bétharram who died in 1924, returning from his Mass. Saubat estimates the duration at about a minute and describes the thickness of the nimbus; no measuring instrument is mentioned^[29]:

"I see indeed, first, a very red face [...] I see very clearly a vapour, a kind of white cloud, that surrounded the whole head. The depth of the nimbus was 15 to 20 centimetres, closer to 20." — Fr. Jules Saubat, testimony cited by Olivier Leroy, p. 158, taken up in Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, vol. 1, Le Jardin des Livres, 2015, p. 72–73^[30]

Bouflet stresses the originality of this description, far removed from the usual hagiographic formulas^[31]. He also reports, concerning Auguste Etchecopar (1830–1897), third superior general of Bétharram, a gentle light on the face and a radiance during adoration. For this latter episode, he cites the testimony of Father Bourdenne, transmitted by Denis Bézy^[32].

Konrad von Parzham: repeated balls of fire over thirty years

The second type of phenomenon — the emission of balls of fire or sparks, distinct from the static halo — is described in the Bavarian Capuchin Konrad von Parzham (1818–1894), doorkeeper of the Altötting convent and canonized in 1934. The witness Nikolaus Hartwanger testifies:

"Sparkling balls of fire came forth from his mouth and rose up to the holy image [...] once, I saw him entirely surrounded by a veil of shining mist." — Nikolaus Hartwanger, cited in Georg Bergmann, Bruder zwischen Gestern und Morgen, Passau, Verlag Passavia, 1974, p. 221, taken up in Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, vol. 1, Le Jardin des Livres, 2015, p. 78–79^[33]

This case derives its main strength from its repetition: Bouflet states that the prodigy "recurred hundreds of times, between 1862 and 1892", and was collected under oath during the beatification and then canonization processes^[34]. A repetition over thirty years, documented by several witnesses testifying under oath in a canonical procedure, meets directly the criterion of duration and religious setting set out by Lambertini.

Narcisa de Jesús Martillo Morán: a cell seen illuminated from the corridor

The third type of case — light observed at the bedside of a dying person — is described in the life of the Ecuadorian saint Narcisa de Jesús Martillo Morán (1832-1869), who died on 8 December 1869 in a béaterio in Lima and was canonised on 12 October 2008^[35]. The account presents a two-stage chain of verification, particularly valuable from a methodological standpoint:

« A sister who was walking along the corridor crossing the house went to see the superior to tell her that, passing by Narcisa's cell, she had seen it all illuminated from within [...]. The superior went there at once to verify the truth of the alleged fact and, opening the door of the room where Narcisa lay, she not only saw the same brightness, which could be made out from outside, but [...] she then realised that Narcisa was dead. » — Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, tome 1, Le Jardin des Livres, 2015, p. 365, citing Roberto Pazmiño Guzmán, Narcisa de Jesús, una mujer de nuestro pueblo, Guayaquil, Impresores Asociados, 1984, p. 140^[36]

Two features distinguish this testimony from the mere accounts of a "radiant face" set aside above: the brightness is said to be visible from outside the room, even before the door is opened, and a second person — the superior — explicitly verifies the first observation before confirming it. The Peruvian Ministry of Public Health, fearing a trick or catalepsy, then imposed a forty-eight-hour exposure of the body, and the prefect Andrés Segura ordered an exhumation on 12 January 1870, thirty-five days after the death^[37].

Yvonne-Aimée de Malestroit: a luminous and burning heart

One testimony concerns the Augustinian nun Yvonne-Aimée de Malestroit (1901-1951). It dates from 16 May 1948, during her lifetime, and therefore belongs to a different category from the account of Narcisa's death. Bouflet reproduces the account of her nurse, transmitted by Paul Labutte:

« Her heart is luminous, and what a light! She has me touch it: it is burning. » — Yvonne-Aimée's nurse, testimony of 16 May 1948, in Paul Labutte, Yvonne-Aimée de Jésus, "ma mère selon l'Esprit", Paris, François-Xavier de Guibert, 1997, p. 705, cited by Bouflet, p. 80-81^[38]

This testimony brings together, as with Marie-Madeleine de' Pazzi and Séraphine de Dieu, a reported luminosity and a warmth perceptible to the touch — a reminder that the two registers often overlap within one and the same mystical experience, without either being reducible to the other.

Bouflet distinguishes lights connected with the place where a deceased person rests from an emanation coming from the body itself. He reports a luminous cross above the body of Peter Chanel, killed at Futuna in 1841, according to the biography by P. Nicolet; at Dülmen, on 9 February 1824, a brightness over the town at the death of Anne-Catherine Emmerich, according to the Emmerick archives: the inhabitants of nearby farms rushed to put out a fire, but found none. On 18 February 1971, three flashes above the grave of Anna Henle lit up part of the cemetery, according to a statement by Father Roesch countersigned by five witnesses. This event is distinct from the illuminated house at Christmas 1896. Bouflet also mentions the burning of Monte Senario at the death of Amideo Amadei, the lights above the body of Beatriz da Silva, and the flashes and flames on the hill of the martyrs of Nagasaki.^[39]

Anna Henle and Symphorose Chopin: a house on fire that is not consumed

Accounts of an illuminated house also concern living persons. They must be distinguished from the funeral lights of Charbel and Rafqa examined below. The Swabian stigmatist Anna Henle (1871-1950) reports that, on Christmas night 1896, she saw a luminous host suspended before her lips; outside witnesses, coming out of midnight Mass, further describe "a house on fire that burned without being consumed, crowned with flames"^[40]. Bouflet specifies that he himself consulted "the copy of the deposition of Abbé Busert, the original of which is kept sub secreto in the diocesan archives of Stuttgart-Rottenburg", so as to bring the account back to a more rigorous objectivity^[41]. An almost identical phenomenon recurred, sixty-nine years later, in the French mystic Symphorose Chopin (1924-1983): at Christmas 1965, her sister Berthe reports a "cross of light over the house", which alerts the local firefighters^[42].

The two biographies cited by Bouflet, those by Franz Teng and Christian Rouvières, present a highly romanticised version of the Anna Henle episode. As for Symphorose Chopin, Bouflet keeps Berthe's testimony, corroborated by other witnesses; Symphorose specifies that she did not herself see the cross over the house, but learned of it during her ecstasy.^[43]

Charbel Makhlouf: a light attested even by a Muslim witness

The lights connected with the tomb of the Maronite monk Charbel Makhlouf (1828-1898), canonised in 1977, are reported by several named witnesses. On the night following his death, 24 December 1898, Brother Élie Mehrini describes a brightness coming from the tabernacle, passing above the body exposed in the church, then returning to the tabernacle. After the burial, Georges Emmanuel reports the glow seen by the inhabitants from their houses. Miladé Chehadé says she observed it three times; she recounts that the superior Antoine Al-Michmichani came to verify it before the exhumation^[44].

Miladé Chehadé specifies that the monks had at first refused to believe the inhabitants. In her account, the repetition of the lights and their verification by the superior prompt the exhumation of the body^[45].

Paul Daher also reports, through Saba Bou Moussa, the observation of the Muslim prefect Mahmoud Hémadé and his men, who had come to look for a criminal near Annaya^[46]. Patrizia Cattaneo places this episode on 8 February 1899 and indicates four gendarmes: the glow, at first faint and then brilliant as a star, is initially taken for a signal between bandits. These details belong to her account of the event^[47]. The article Saint Charbel Makhlouf sets out the biography and the healings attributed to the saint.

Rafqa Ar-Rayès: "I could see one by one the leaves of the oak"

A comparable dossier concerns the Lebanese nun Rafqa Ar-Rayès (1832-1914), canonised in 2001, whose grave is likewise the subject of observations of nocturnal light. Dorgham Al-Koury Khaïrallah, who reports two observations on two different nights, specifies the effect of the light on its surroundings^[48]:

« Thanks to that light, I could see one by one the leaves of the oak that stands opposite the vault. » — cited in Joseph Mahfouz, La servante de Dieu, sœur Rafqâh..., Roma, Postulazione, 1980, pp. 125-126, taken up in Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, tome 1, Le Jardin des Livres, 2015, p. 87^[49]

This detail — the ability to distinguish the leaves of a tree by means of this light — indicates an effect on the environment. It ties in with the question raised by Lambertini's first criterion, that of a brightness surpassing the surrounding lighting, without providing any measurement of its intensity. The article Saint Rafqa presents her entire life and her cause for canonisation.

Three cases, although frequently cited in popular literature as "luminous phenomena", must be classified with particular caution: they describe a colour, a transparency or a freshness of complexion, without any witness explicitly asserting an emission of light illuminating the environment.

Maria del Carmen González Valerio: a "radiant light" at the moment of death

The Spanish child Maria del Carmen González Valerio (1930-1939) dies in Madrid on 17 July 1939, at nine years of age, after a painful sepsis. Her Carmelite biography describes the moment of death as follows:

« Now, at the moment she breathed her last, a heavenly beauty spread over her face. It was a spiritual, luminous beauty, as if her body had become an alabaster vessel rendered translucent by a radiant light that had been lit within it. » — Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, tome 1, Le Jardin des Livres, 2015, p. 353-354, citing La niña que se entregó a Dios, Carmelitas Descalzas de Aravaca, 1980, p. 121^[50]

The text continues with a more objective observation: the body "gave off not the slightest bad smell", retained "its full flexibility", and the face remained so fresh that the official charged with issuing the burial permit at first refused to do so^[51]. This chain of concrete signs (absence of smell, suppleness, documented administrative refusal) gives the account a grounding that the mere literary formula of the "radiant light" would not have.

Librada Ferrarons and Maria Anna Josefa Lindmayr: the translucency test

The Catalan weaver Librada Ferrarons (1803-1842) dies in Olot on 21 June 1842, after ecstasies in which her biographer says she was already "irradiated":

« The skin became of an alabaster whiteness, and luminous, as she appeared irradiated at the most beautiful moments of her ecstasies. The eyes shone like two stars. » — Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, tome 1, Le Jardin des Livres, 2015, p. 407-408, citing Mario Nanteli, La tessitrice di Olot, Liberata Ferrarons, Milan, Ed. Ancora, 1963, p. 125^[52]

The case most useful for precisely distinguishing translucency from light proper is that of the Munich Carmelite Maria Anna Josefa Lindmayr (1657-1726). Eight days after her death, a physician to the Wittelsbach court, Dr Temperer, summoned two other doctors and three surgeons for a collective examination, in the presence of six Carmelites and the community. The official report states:

« All the limbs are very beautiful, translucent, like a hand held up in the evening before a flame, with the same colour of a beautiful pink. » — cited in Bonifatius Günthner, Maria Anna Josefa Lindmayr: Prophetin Gottes und Helferin der Armen Seelen, Myriam Verlag, 1976, p. 236, taken up in Joachim Bouflet, Encyclopédie des phénomènes extraordinaires dans la vie mystique, tome 1, Le Jardin des Livres, 2015, p. 429^[53]

The comparison chosen by the doctors themselves is decisive: a hand before an external flame is translucent; it does not emit its own light. This report, precisely because it is a collective medical observation and not a devotional account, makes it possible to distinguish a rosy translucency — a phenomenon of colouration and transparency of the tissues — from a genuine emission of light.

A hierarchy of evidentiary weight among the cases presented

Not all the cases retained so far have the same documentation. One must distinguish the quality of a deposition from the independence of the witness: an oath or a beatification process provides a framework for the account, without automatically making its author an outsider to the subject's circle.

These criteria assess the accounts, without ranking the holiness of the persons. Brother André's file combines a named witness, a comparison with electric lighting and a duration estimate. Narcisa's describes a subsequent verification; Konrad's, a prolonged repetition. Neither the precision of a memory nor its recording under oath replaces an instrumental measurement.

A filmed phenomenon presented before a medical society

The most fully documented medical case in the corpus concerns Anna Monaro, observed at Pirano in 1934. Padua refers to the medical presentation reported by Aimé Michel on the basis of Herbert Thurston, and not to the place where the patient was observed. The physician Giocondo Protti published his own account in the Illustrated London News of 19 May 1934, under the title "The Luminous Woman: The Mystery of Anna Monaro"^[54]. Michel summarises the transmission of the case:

« Il se trouve que ce phénomène est un de ceux que la science a pu étudier à loisir, quoique sans en donner d'explication : on trouve dans Thurston le compte rendu succinct d'un cas observé et filmé en 1934 dans un hôpital italien. Un rapport fut présenté, avec le film, devant une société médicale dépendant de l'université de Padoue, par le médecin qui avait étudié le cas, le Dr Protti. » — Aimé Michel, Métanoia — Phénomènes physiques du mysticisme, Albin Michel, 1986, p. 231-232, referring to Herbert Thurston, Phénomènes physiques du mysticisme, p. 198-199^[55]

The article signed by Protti describes the observation of 11 April, in the presence of Professor Fabio Vitali. It reproduces a film strip of 54 frames, stated to run at 16 images per second, as well as graphs. Protti reports a pulse rising from 70 to 140 per minute and respiration from 24 to 48 per minute. He describes the use of an electroscope, a Faraday cage and an electrocardiograph. He notes, however, that the clothing and blankets were not fully removed: the light appeared at chest height, between the blankets^[56].

The discussion published by J. B. Bateman in Nature on 9 June 1934, p. 860 constitutes another contemporary document. On the basis of press accounts, including Protti's, Bateman mentions an emission of about three seconds and a photograph taken at 1/16 of a second. These are not measurements made by Bateman on the patient^[57].

A luminosity correlated with a precise physiological constellation

The report summarised by Thurston, and then by Michel, does not present the luminosity as an isolated phenomenon, but as associated with a set of observable physiological signs:

« Ce Dr Protti remarque, dans son étude, que le sujet, une femme, était "en proie à une idée fixe de caractère religieux", que l'apparition de la luminosité était en rapport avec des troubles neurovégétatifs, notamment une accélération des rythmes cardiaque et respiratoire, des sueurs profuses, de fortes variations des activités endocriniennes et surtout avec des périodes de jeûne absolu, détail qui semble avoir beaucoup frappé le médecin. » — Aimé Michel, Métanoia — Phénomènes physiques du mysticisme, Albin Michel, 1986, p. 232^[58]

This description links observable signs — pulse, respiration, sweating — to a neurovegetative and endocrine interpretation. The heart and respiratory rates appear in Protti's account; the quoted summary, however, provides no hormonal assay that would allow the "endocrine variations" to be measured. The physiological context described is therefore not sufficient to establish a luminescent mechanism^[59][60].

The hypothesis of cutaneous phosphorescence

Dr Protti proposes a biochemical mechanism to account for the observed luminosity:

« Il se pourrait, dit-il, que, lors des crises où s'observe la luminosité, des composés soufrés contenus dans la sueur fussent excités sous l'effet de radiations exceptionnellement énergiques émises par le sang. » — Aimé Michel, Métanoia — Phénomènes physiques du mysticisme, Albin Michel, 1986, p. 232^[61]

Michel points out that Thurston's summary does not explain why Protti locates the origin of the supposed radiation in the blood^[62]. The photographic film strip published by Protti does not, by itself, constitute a measurement of the light's spectrum, its flux or its anatomical source. The recorded image and the biochemical hypothesis are two distinct elements of the record.

The critique of the supposed radiation

The contemporary critique of Bateman concerns the proposed mechanism. The "mitogenetic" radiation invoked by Protti remains, in his view, insufficiently established; even if it existed, its intensity would be too weak to produce visible fluorescence. Bateman recalls biological chemiluminescence and also mentions luminous bacteria as a possible explanation for certain accounts, without demonstrating their presence in this patient. His article is a theoretical discussion based on the press, not a report of a clinical examination^[63]. Bouflet notes this dispute in his own dossier^[64].

Aimé Michel likewise rejects the hypothesis of "radioactive blood", invoking in polemical fashion fatal consequences for the patient and those around her^[65]. His passage, however, provides neither dose, nor radiation energy, nor exposure calculation. It therefore does not constitute a dosimetric demonstration. The documentary result is more precise: the proposed explanation is not established, and the 1934 debate alone neither reproduces the phenomenon nor determines its cause.

Domenica Patania: a five-year medical follow-up

Bouflet links to luminous manifestations the case of Domenica Patania, known as Mamma Minna, born in 1917 and living near Paterno in Sicily. Affected by near-total blindness related to diabetes, she said she had been cured of cancer in 1960 after an apparition of Saint Rita. During her mystical experiences, her eyes were described as intensely luminous; the same accounts mention the emission of fresh rose petals from her mouth^[66]. Dr Mariano Grasso, a physician in Catania, observed her for five years. The checks detailed by Bouflet concern mainly the petals: this duration must not be equated with five years of optical measurements of the eyes^[67].

The body's natural light: an emission too faint for the eye

The human body does emit a very faint light. In 2009, Masaki Kobayashi, Daisuke Kikuchi and Hitoshi Okamura photographed it in five volunteers, with a camera cooled to −120 °C. After fifteen minutes of dark adaptation, each image required twenty minutes of exposure. The measurements, repeated every three hours over three days, showed a maximum in the late afternoon^[68].

This emission, associated with cellular metabolism, is about a thousand times weaker than the sensitivity threshold of the naked eye. The images do not reproduce the temperature distribution of a thermal photograph. The study thus establishes a measurable natural emission; at this intensity, it does not account for an illuminated cell or a tree whose leaves would become visible at night^[69]. Applying this explanation to mystical accounts would require measurements showing sufficient amplification: the mere existence of "biophotons" does not provide such a demonstration.

The dossier of luminous phenomena is not limited to the bodies of mystics. A smaller subset concerns liturgical objects or pious representations.

In Ravenna, in the church of San Pier Damiani, Bouflet reports a luminescence from the heart of a statue of Our Lady of Fátima on 3 November 1972, after weeping reported since 12 September. The notice mentions a liquid identified by analysis as human blood and fragrances sometimes accompanying the tears and the bleeding, without reproducing any report or specifying the laboratory or protocol. It states that the Archbishop of Ravenna did not recognise the supernatural character of the events. This Italian episode is distinct from the Portuguese apparitions of Fátima.^[70]

Bouflet reports for January 1970 an emission of rays of light from a statue of the Sacred Heart coming from the Church of Saint Joseph and held by Maria Baumann since 1968. He describes it among the transformations of the wounds preceding their bleeding: swelling of the heart, hollowing and swelling of the wounds on the hands and feet. His notice states that the events, surrounded by great discretion, were submitted to an investigative commission, with no judgment issued by ecclesiastical authority^[71].

Stolen hosts recovered thanks to a light

Bouflet brings together three accounts of stolen hosts then recovered thanks to a brightness: Ettiswil, in Switzerland, after the theft of 23 May 1447; Huesca, in Spain, after that of 30 November 1648; Paterno, near Naples, where the hosts are recovered in January 1772, more than a month after their disappearance^[72]. At Ettiswil, the swineherd Margreth Schulmeister and another shepherdess notice the light of a bush; the inhabitants in turn discover the host there. Bouflet emphasises the ecclesiastical investigation and the construction of a votive chapel: the account has a location and a cultic history, beyond the mere literary motif of the light^[73].

Luminous statues and icons: the case of Akita

A final subtype concerns lights observed around a holy image or statue. Bouflet notably describes the statue of Our Lady of Akita, in Japan, surrounded from the outset of the phenomenon by "mysterious lights", then "suddenly glowing" on 29 September 1973, at the precise moment when its stigmatic wound disappears^[74]. This dossier, recognised by a pastoral letter of Bishop Itô, Bishop of Niigata, on 22 April 1984, is dealt with in its entirety by the article The Shrine of Our Lady of Akita, to which this article refers rather than duplicating its content.

The motif of a light associated with prayer is not peculiar to Christianity. Aimé Michel cites the Neoplatonist philosopher Iamblichus on the basis of Eunapius^[75]. The passage from the Lives of the Philosophers and Sophists does, however, have a precise structure: the disciples question Iamblichus about a rumour passed on by his servants, according to which he would rise up while praying, his body and his clothes taking on a golden colour. Iamblichus laughs, then rejects the account. Eunapius therefore does not offer here a deposition by disciples affirming that they themselves observed the phenomenon^[76].

This page attests to the circulation of the motif in Antiquity; it is not sufficient to establish any luminosity of Iamblichus. The comparison of religions therefore requires comparing the documents as well: a rumour contradicted in its own source does not have the same status as an observation claimed by a named witness. Even when a physical effect is established, its mere resemblance to another account does not determine its spiritual significance.

What a luminous phenomenon proves, and what it does not prove

Objection 1 — "It is merely a reflection or an ordinary lighting effect"

Reply: the objection is the first to be examined in each case. Adélard Favre, a witness of Brother André, then seeks to compare his observation with the electric lighting of the shrine; Brother Ludger takes part in this subsequent verification^[77]. This procedure documents a concrete comparison, but Ludger does not constitute a second witness of the initial scene and the test does not necessarily reproduce all the conditions of the observation.

Objection 2 — "Simple vasodilation or a fever is enough to explain a radiant face"

Reply: a colouring or translucency of the complexion is not enough to establish a light emission. The descriptions of Mary Magdalene de' Pazzi, Alexia González Barros, Librada Ferrarons and Lindmayr thus differ from the accounts where a witness describes an effect on the environment (Brother André, Narcisa de Jesús, Rafqa). The medical report on Lindmayr gives a precise comparison: a hand in front of an external flame is translucent, it does not emit its own light^[78].

Objection 3 — "Collective suggestion and devotional hagiographic amplification bias all these accounts"

Reply: this factor must be examined in every dossier. The passer-by who did not know Vincenzo Pallotti and the Muslim prefect who came looking for a criminal near Annaya do not occupy the same position as intimates of the mystic^[79][80]. This does not make them infallible; it gives concrete circumstances to confront. Conversely, Michel calls Abbé Manesse, who recounts a halo around Anne-Catherine Emmerich, a "fervent admirer" and notes the passions that run through his text. The judgment here bears on the transmission and tone of the account, not on a demonstration that the event would be impossible^[81].

Objection 4 — "The Protti report passes through too many intermediaries to be reliable"

Reply: the Michel–Thurston chain does exist, but the signed account by Protti and his printed photographic strip have also been preserved. The observation therefore does not rest solely on late summaries^[82]. This does not resolve all experimental questions: a photograph of light proves neither its bloody origin nor the absence of any other light source. Bateman's rejection of the proposed mechanism must be distinguished from an experimental refutation of the observation itself^[83].

Objection 5 — "A non-reproducible phenomenon cannot be considered a scientific fact"

Reply: one must distinguish the reproduction at will of an event from the scientific examination of the traces it leaves. A singular event can be studied; what matters is the quality of the observations, the instruments and the controls available. But the absence of reproducibility does not equate to the absence of historical evidence: it merely invites us to distinguish a fact established by testimony — on the same footing as most ordinary historical facts — from a fact demonstrated by controlled experiment. Refusing in advance any fact known through testimony alone would amount, in Michel's phrase, to never being able to be warned of an error of judgment^[84].

Objection 6 — "Similar phenomena exist outside Christianity, so they prove nothing specifically Catholic"

Reply: a resemblance between accounts does not constitute an equivalence of proofs: the passage from Eunapius on Iamblichus transmits a rumour rejected by the person concerned^[85]. But even a materially established luminous effect would not be enough to identify its spiritual origin. Lambertini's criteria add to the examination of the phenomenon the context of prayer, the signs of uncommon virtues in the subject and the spiritual fruits in the witnesses^[86].

Objection 7 — "Even once established, an unexplained physical fact does not prove a divine origin"

Answer: the absence of a physical explanation does not by itself identify a divine cause. Lambertini's criteria also require a context of prayer, signs of uncommon virtues, and spiritual fruits in the witnesses^[87]. The material examination of the phenomenon and the discernment of its meaning are therefore two distinct steps.

The following table compares the phenomena reported among the canonised saints mentioned in this article. Canonisation concerns a person's holiness; it does not automatically authenticate each of the extraordinary accounts in their biography.

The intensity or spectacular nature of the reported phenomenon in no way predicts the ecclesial judgement: Konrad von Parzham, whose prodigy repeats itself hundreds of times over thirty years, and Pier Giorgio Frassati, whose luminous vocabulary Bouflet himself refutes as "pious fiction", are both canonised: the judgement on their holiness is distinct from the evaluation of each luminous account. The 1934 medical case raises a different question: the presence of a light and its possible mechanisms. A medical observation is not a judgement on the patient's holiness.

The approach set out by Bouflet links three steps: first establish the fact, with its witnesses, duration and context; then seek the possible secondary causes — reflection, translucency, fever, suggestion; finally, conclude to a spiritual meaning only in the light of the lasting fruits of an entire life. Light, when it comes from God, is never itself holiness: it may accompany it, but it never constitutes it.

The theologian Antonio Blasucci offers this interpretation, expressly restricting his remarks to phenomena of divine origin:

"When it is a question of such a phenomenon of divine origin, only one theological explanation is possible, that of an irradiation which, from the spirit in contact with God, is transmitted to the body [...] one can see in this phenomenon a sort of anticipatory irradiation of the glorious brightness of bodies in the new world of the resurrection." — Antonio Blasucci, article "Phénomènes lumineux", Dictionnaire de Spiritualité, Beauchesne, fasc. LXII-LXIII, 1976, col. 1184-1188^[89]

He thus links bodily light to the Christian hope of the resurrection. The spiritual issue is the transformation of the whole person by God, not the search for a spectacular manifestation.

• Incendium amoris — mystical heat, a neighbouring phenomenon often intermingled in the same testimonies.
• The stigmatics — hub on stigmatisation, another mystical psycho-physiological phenomenon.
• The incorruptible bodies — the preservation of the body after death, distinct from the transfiguration of the face.
• Levitations — another bodily phenomenon linked to ecstasy.
• Inedias — total abstinence from food among certain mystics.
• Other mystical phenomena — an overview of the less frequent phenomena.
• Saint Charbel Makhlouf — complete life and attributed miracles.
• Saint Rafqa — complete life and cause of canonisation.
• Saint Pier Giorgio Frassati — complete biography.
• The shrine of Our Lady of Akita — complete dossier on the luminous statue and its recognitions.
• Discernment of supernatural phenomena — Catholic criteria of prudence.
• What is a miracle? — general theological framework of sign and miracle.