A Dual-Disciplinary Approach to Joan of Arc’s Illumination

Introduction

On May 30, 1431, Jeanne d’Arc was executed as a relapsed heretic and burned at the stake before an estimated crowd of about 10,000 people. Condemned by an English ecclesiastical court, her descriptions of divine voices and luminous visions were dismissed by the Inquisition as demonic heresies. Yet her visions altered the course of the Hundred Years’ War. Her actions prompted the lifting of the Siege of

Orléans and secured the coronation of Charles VII. So, were these triumphs the results of divine instruction from angels, or simply the products of an underlying neurological disorder? The difficulty is in determining whether either can be fully understood without the other. If neuroscience can explain how such encounters occur, does that settle their meaning? And if theology can interpret their significance, can it also ignore the biological conditions through which they arise in the first place? To insist on an absolute choice between them is to oversimplify the problem. Even if neuroscience explains how religious experiences occur, it cannot by itself determine what they mean, whether they are revelatory, or why they hold such an unshakable grip on human belief. Rather, neuroscience and theology are not rivals; they explain the same phenomenon at different levels of analysis.

Analysis

Contemporaries of Jeanne d’Arc interpreted her either as divinely inspired or as deceived by demonic forces. Modern clinical science, on the other hand, proposes a material explanation for her experiences. Neurologists Giuseppe d’Orsi and Paolo Tinuper, drawing on the transcripts of her 1431 trial, suggest that Jeanne’s reported episodes are consistent with a form of temporal lobe epilepsy known as Idiopathic

Partial Epilepsy with Auditory Features (IPEAF). They note that her accounts of brief episodes, often involving a “great light” and triggered by church bells, are consistent with descriptions of an ecstatic aura. Acknowledging this biological substrate is essential. After all, we are physical beings—all human experiences, no matter how transcendent, have to occur within the framework of our physical constitution. Nevertheless, identifying a biological mechanism does not, by itself, entirely exclude the possibility of an external source.

To dismiss the objective validity of an encounter simply because we can observe neurons firing is to commit the genetic fallacy. That is, to confuse the physical origins of an event with its ultimate value as truth. An explanation is not complete simply because it identifies an underlying cause. It must also account for the phenomenon being explained. Explaining the cause of a belief is not the same as evaluating the truth of that belief. If any belief can be traced to objective biological processes, then this observation must apply equally to other religious beliefs, scientific theories, historical judgments, and mathematical insights. The presence of a neurological cause does not, by itself, establish whether the belief is true or false. For example, a mathematician may discover a theorem while daydreaming, but the truth of the theorem depends on its proof, not on the circumstances of its discovery.

Plantinga argues that certain beliefs may be properly basic. That is, rationally held without inferential proof. If religious experience functions in this way, then identifying its neurological correlates does not, by itself, undermine its epistemic warrant. Just as most people trust their sensory perception unless given reasons to doubt it, it can be argued that religious experiences have an apparent credibility that cannot be

dismissed solely by identifying their neurological correlates.

Centuries earlier, Thomas Aquinas maintained that God works through secondary causes within creation. From this viewpoint, a neurological account of religious experience would not necessarily compete with a theological one. Both would describe different facets of the same event. In Jeanne’s case, even if her

visions possessed a neurological basis, a theological account need not regard that basis as excluding divine action. Years later, William James leveled a similar critique at what he named “medical materialism,” or the view that religious experiences can be explained away by identifying their physiological causes. For James, the crucial question was not where an experience originated, but what followed from it.

Critics might argue that theology is irrelevant here, since fields such as psychology, sociology, and anthropology can readily explain how people interpret religious experiences within their respective cultural contexts. These alternative disciplines, however, are primarily descriptive. They may explain why someone might believe an experience is divine, but not whether that belief is warranted or true. By itself,

theology does not automatically establish the objective truth of religious claims, but provides the outline for evaluating them when an experience is claimed to originate from a transcendent source. Neuroscience can explain the occurrence of the experience. Psychology can analyze its cultural interpretation. But theology considers whether the experience might actually correspond to something entirely beyond the

human mind.

But dependency runs both ways. Cut off from empirical facts, theology is just as helpless. In Book IV, Chapter XIX of An Essay Concerning Human Understanding, titled “Of Enthusiasm,” John Locke targets those who supplant personal, private emotional intensity for objective evidence. Locke warns that subjective impulses often arise merely from the “conceits of a warmed or overweening brain,” yet they

dictate human action more powerfully than reason or revelation. For Locke, the hallmark of enthusiasm is that its proponents “are sure, because they are sure”—relying entirely on internal light without an external, empirical check. Locke argued that if internal persuasion alone were enough reason to prove a divine command, then “every fancy may be a revelation.” Locke was not rejecting the possibility of

revelation itself, but he insisted that any claim to revelation must remain accountable to reason. Without scrutiny through reason or natural science, a wholly theological schema becomes subjective and prone to bias.

The challenge of distinguishing genuine revelation from illusion or mental disturbance has been known to Christianity for centuries. For this reason, historical traditions of discernment arose to examine religious experiences, but in terms of their alignment with established doctrine and set moral consequences. Theology, therefore, does not simply accept claims to divine revelation at face value. Rather, it attempts to

determine whether such experiences credibly point beyond the individual mind. In this respect, theology addresses questions that remain even after the neurological mechanisms of an experience have been identified.

Neither neuroscience nor theology can fully answer the question alone. To expect that any single field will account for the full range of human knowledge just because it is internally coherent and rigorous is illogical. An entirely neurological explanation risks reducing meaning to mechanism, while a theological explanation risks forfeiting the checks of evidence and rational analysis. So, each discipline addresses different aspects of the issue while using its own standards of evidence and reasoning.

Conclusion

Ultimately, it is irrelevant whether neuroscience or theology should supplant the other. The relevant issue is whether either discipline can independently account for religious experience. If neuroscience can explain how religious experiences occur, and theology can examine what, if anything, they reveal, then the mistake lies not in choosing the wrong discipline, but in assuming that one discipline must replace the

other.