Accounts of religious or mystical experiences are frequently cited as evidence for the existence of God. Such experiences seem to defy ordinary explanations and demand the existence of a supernatural power to account for them. The argument from religious experience therefore deserves philosophical consideration, and any analysis must start from an understanding of the nature of such experiences.
Accounts of religious experience suggest a variety of different types, although it is possible to identify a few common elements. For an experience to count as religious in this sense, it must involve a direct experience of God or some transcendent reality. The nature of the experience can vary significantly: St Augustine famously heard a child’s voice chanting tolle, lege (‘pick it up and read’) which impelled him to open his Bible; St Paul was blinded on the road to Damascus; others have found insight after prayer or ritual. Such experiences may be mediated through everyday events (a sunset, a flock of birds) or extraordinary ones (a burning bush, a vision of the Virgin); or they may be directly experienced, for instance in a meditative state. In each case, however, the subject claims a revelation of some independent and transcendent reality.
If such an external reality is indeed accessible, we might expect there to be a common core to such experiences. In his classic account (The Varieties of Religious Experience, 1902 cf Lecture XVI), William James identified four characteristics. Religious experiences are ineffable, that is, they are so unusual as to defy description in ordinary terms (and are therefore difficult to communicate); they have a noetic quality, offering insight into universal or eternal truths; they are transient, offering a brief intensity and a lingering sense of profundity; and they are passive, that is, the subject experiences a higher power working through them. Other philosophers have identified elements similar to those cited by James, although it is worth noting that ineffability is controversial in this account and should perhaps be restricted to a certain type of mystical experience.
Philosophers also tend to exclude certain types of event when discussing these matters. Firstly, religious experiences should be distinguished from religious feelings as these are affective but not cognitive. Just as in everyday life an experience of something is generally more than just a subjective feeling – it involves a perception of an object – so a religious experience must in some sense be a perception of a transcendent reality. Although religious feelings will often accompany such experiences, they are not the same thing.
Secondly, the religious nature of certain experiences can be understood as interpretative rather than perceptual. In these cases, there is no transcendent reality to be experienced: instead, the subject uses their existing beliefs to interpret an ordinary event as meaningful. Perhaps the childlike voice heard by Augustine simply belonged to a neighbour, and there was nothing divine about the words: nevertheless, Augustine himself understood the moment in terms of Christian revelation and thus began his conversion. In such cases it is the structure of the subject’s beliefs and not the truthfulness of the experience that matters. Therefore these examples are generally excluded from discussion of religious experience.
It seems, therefore, that a valid religious experience must be analogous to our perceptual experiences: that is, there must be both a subject and an independent reality that gives rise to the experience. Alvin Plantinga has made use of Calvin’s claim that humans have a sensus divinitatis (sense of the divine), an additional sense or faculty allowing for knowledge of God. History provides many examples of saints and mystics who claim to have experienced the divine, whether those experiences take the form of natural phenomena, dreams, prophecies, religious conversion or vaguer sensations of power, unity, joy or love. In a less dramatic way, we may ourselves have undergone experiences that seem unusually significant or otherwise inexplicable. The philosophical question is how far such experiences provide evidence for the existence of God.
If we understand religious experiences to be of a perceptual nature, then it is possible to argue that they represent evidence for the existence of God. In ordinary life, our beliefs are based on our perceptions: seeing the book on the table justifies my belief that the book is on the table. Religious experiences can therefore provide justification for believing in God or a transcendent reality. Such experiences often give rise to absolute certainty on the part of the subject, however it should be noted that such certainty is no guarantee of the truth of the experience: a person can be certain of an experience, even if that experience lacks a real object (a hallucination, for example).
Richard Swinburne has argued from the ‘principle of credulity’ that we must therefore take religious experiences seriously as evidence for the existence of God.
Now it is a basic principle of rationality, which I call the principle of credulity, that we ought to believe that things are as they seem to be (in the epistemic sense) unless and until we have evidence that we are mistaken... And it is another basic principle of rationality, which I call the principle of testimony, that those who do not have an experience of a certain type ought to believe any others when they say that they do – again in the absence of evidence of deceit or delusion. Is There a God? p131-3
Since religious experiences must have an object, the best explanation for the experience is the existence of that object – in other words, God or a similar supernatural power. This reasoning is usually called the argument from religious experience.
Problems arise when we try to compare these experiences to more common types of event. Religious and mystical experiences must be unlike everyday experiences: this difference is what allows the subject to argue to a supernatural, rather than merely natural, explanation. Analogy is therefore common: the religious experience is compared to a familiar event in an attempt to communicate its meaning. But analogies are poor tools of reason: it is the difference between a supernatural and a natural experience that is at issue and that is precisely what any analogy fails to articulate.
A second objection involves the verifiability of the experience. If I see the book on the table, my perception can be confirmed by my reaching out to touch it, and by others who can also see and touch the book. Religious experiences do not seem to be verifiable in the same way. Some philosophers have claimed that such experiences can be verified in a less direct way, by referring to other experiences or even arguments from natural theology. It should also be noted that many people have searched for God without result: prayers have gone unanswered, suffering unrelieved, and so on. It is not clear how much value we should place on such failures, or why they should carry less epistemic weight than accounts that corroborate religious claims.
Cultural diversity also presents a problem for the authority of religious experience. Individuals around the world experience the divine in different and often contradictory ways. This is a problem in the same way that conflicting eye-witness reports undermine grounds for belief. Some philosophers have therefore claimed that such experiences are natural effects of culture rather than perceptions of the divine. It should be noted, however, that individuals often experience the same thing differently (a work of art, for example) and that all of our experiences are shaped to some extent by our cultural and conceptual framework.
The strongest objection to the value of religious experience is the existence of naturalistic explanations. While the subject of a religious experience may claim to have encountered the divine, a psychological or neurological account may explain the event fully without requiring any external transcendental reality. Psychopaths and serial killers routinely claim to have heard the voice of the Devil (or God) urging them on, and few people these days would see this as evidence for anything but mental illness. J L Mackie makes the point that the nature of any religious experience is equally explicable in psychological terms:
... since it is also admitted that those [experiences] which the theologian would ascribe to God are not intrinsically distinguishable from those which he would initially ascribe to the devil, it follows that even what he classes as genuinely religious experiences do not intrinsically resist explanation in purely human terms. And this in itself seems fatal to any argument from religious experience to any supernatural conclusions whatever. The Miracle of Theism p181
While psychological explanations do not rule out the possibility of a genuinely religious experience, they do at least offer an alternative and (perhaps) more plausible account.
Those who undergo such experiences often make the mistake identified by David Hume of attributing more to the cause than is warranted by the effect. A religious experience may indicate some supernatural power, but not which one; nor will it identify the particular attributes of that power (such as omnipotence, omniscience, benevolence). In fact, there is good reason to suppose that we would not be able to authenticate such qualities even if we encountered them: how would we recognise an entity as eternal, infinite or omnipotent? These considerations significantly limit the scope of any conclusion that may be drawn from religious experience.
One final question is how far such experiences provide grounds for the belief of others. My experience may be compelling evidence for me, but how should you respond when I relate it? Assuming that the experience is intelligible (and not ineffable), my testimony should perhaps be at least as convincing as any other claim I make. However, religious experiences by their nature are remarkable: as David Hume noted, any testimony of miraculous events should be treated sceptically. It seems that such experiences, however compelling for the subject, have little or no authority over the reason of others. As Thomas Hobbes put it:
For if a man pretend to me that God hath spoken to him supernaturally, and immediately, and I make doubt of it, I cannot easily perceive what argument he can produce to oblige me to believe it... To say He hath spoken to him in a dream is no more than to say he dreamed that God spake to him; which is not of force to win belief from any man that knows dreams are for the most part natural, and may proceed from former thoughts... To say he hath seen a vision, or heard a voice, is to say that he dreamed between sleeping and waking... To say he speaks by supernatural inspiration is to say he finds an ardent desire to speak, or some strong opinion of himself, for which he can allege no natural and sufficient reason. So that though God Almighty can speak to a man by dreams, visions, voice, and inspiration, yet He obliges no man to believe He hath so done to him that pretends it; who (being a man) may err and (which is more) may lie. Leviathan XXXII