William James defined religious experience for the purposes of his Gifford Lectures, later published as “The Varieties of Religious Experience” (1902).  He began by limiting the scope of his enquiry, focusing on “the feelings, acts, and experiences of individual men in their solitude, so far as they apprehend themselves to stand in relation to whatever they may consider the divine” p.32  In this way, James suggested that corporate experiences like those at Fatima, Medjugorje and Toronto are less credible than individual experiences.  James was influenced by Durkheim’s dismissal of religious experience as “an effervescent group phenomenon” more likely to be caused by mass hysteria than by God’s actions, so chose to concentrate on individual experiences despite the difficulty of proving such.   James went on to outline “four marks which, when an experience has them, may justify us in calling it mystical…” namely passivity, transiency, ineffability and being noetic, and this definition has been important in shaping subsequent research into religious experience.  Nevertheless, James’ definition has been criticised both for being too broad and conversely, for being too limited.  Yet, despite these criticisms, James’ definition remains the best to use when researching this topic.   

Importantly, James’ four marks define mystical experiences, which are just one type of individual religious experience.  James spends two lectures and two chapters of “The Varieties of Religious Experience” discussing mystical experiences, but these fall towards the end of a much longer project.  James begins Lecture II “Circumscription of the Topic” by warning of the dangers of rigid definitions.  He wrote: “The theorizing mind tends always to the oversimplification of its materials. This is the root of all that absolutism and one-sided dogmatism by which both philosophy and religion have been infested.” p.24  This explains why James calls his criteria the four “marks”, suggesting that these are pointers to the credibility of an experience rather than necessary pe-conditions for discussing an experience.  Given that it is made up of “marks” or indicators of an experience being genuine, James’ definition is a useful one because it helps the student to analyse experiences and identify areas in which the experience is more, or less, likely to be controversial.  For example, the experiences of Julian of Norwich were certainly noetic, containing knowledge she did not have before, and they were also arguably transient and ineffable, despite the facts that she experienced a series of night-long experiences and described them at length in common English.  While Julian was not experimenting with drugs or sensory-deprivation in order to provoke an experience, the fact that the experiences all occurred when she was gravely ill might suggest they were not passive; it is easy to imagine that they could have had a physiological and/or psychological cause, even if Julian was not aware of it.  Of course, James’ marks raise questions about some important experiences, like those of St Teresa of Avila, which were neither passive nor really transient.  Yet this does not take away from the usefulness of the marks unless one misinterprets the marks and uses them as a rigid definition.  James suggests that conversion experiences have their own four characteristics – loss of worry, perceiving new truths, perceiving a sense of newness in all things and the ecstasy of happiness produced – and this shows that James did not intend his “definition” to be used as a benchmark but rather as a working definition as part of research.  In this way, James’ definition remains the best to use when researching this topic.   

An early critic of James’ definition was Rudolf Otto, whose “The Idea of the Holy” was published in 1917.  Like James, Otto defined religious experience in terms of solitary encounters with what subjects consider to be the divine and like James Otto argues that genuine experiences are ineffable – in order to signify this, Otto resorts to using Latin terminology such as “mysterium tremendum et fascinans” when describing their characteristics.  Nevertheless, Otto criticised James for not specifying that genuine religious experiences must be non-rational.  He wrote “William James has collected a great number of [examples of religious experience] without, however, noticing the non-rational element which thrills in them…” p37-8 While they disagreed with Otto in other aspects of their definitions, Walter Stace and Paul Tillich would both agree with his point about the necessary non-rational nature of religious experiences.  Despite this, James’ broader definition is more useful when it comes to researching religious experience because insisting that religious experiences are non-rational tends to exclude revelatory experiences, upon which religions depend, from consideration when it is these that there is a real need to study.  For example, Moses’ experience at the burning bush in Exodus 3 is one in which Otto’s “mysterium tremendum et fascinans” (the tendency to invoke fear and be compelling simultaneously) is evident, and in which Moses’ reason is shown inadequate by God’s revelation that He is “I am that I am”, and yet to dismiss the other element of Moses’ experience in which God instructs Moses to return to Egypt and explains why as a creative means of expressing something ineffable and non-rational would be to undermine the belief that Moses received and recorded God’s words faithfully.  This would be devastating to the three world religions that take the books Moses wrote as their Scriptures.  For another example, the Prophet Muhammad’s experience on the Night of Power could be described as numinal and ineffable, but it is difficult to describe it as non-rational in the way that Otto demands.  Also, Otto’s definition is very narrow in suggesting that the object of all genuine experiences is the same – the numen – and in suggesting that genuine experiences must invoke fear “mysterium tremendum”.  James’ broader definition makes no such claim and would include reassuring experiences and those associated with a sense of love and unity.  Other scholars, including Stace, Tillich and FC Happold argue that there is no need for genuine religious experiences to invoke fear of any kind.  For these reason James’ broader definition of religious experience is of more use when researching this topic than Otto’s. 

A more recent critic of James’ working definition has been Richard Swinburne.  For Swinburne, James’ four marks are useful in defining a particular type of religious experience, namely solitary mystical experiences, but these represent only one type of religious experience so a much broader definition is necessary when studying the whole topic.  Swinburne proposed a five-fold definition of religious experience as part of his “Existence of God” (1994), arguing that an experience which can be described using everyday language (e.g. a dream), an experience which cannot be described using everyday language (e.g. a mystical experience), a conviction that God has been experienced in some way despite lack of material evidence, perceiving a perfectly normal phenomenon (e.g. a sunset) or perceiving a very unusual public object (e.g. the resurrection) might all be genuine religious experiences.  Importantly, Swinburne’s definition includes corporate experiences, which James chooses to exclude from his discussion for not being “the feelings, acts, and experiences of individual men in their solitude”, and Swinburne’s definition also includes witnessing miracles, which may not conform with James’ mark of ineffability.  Caroline Franks Davis supported Swinburne’s broad approach to defining Religious Experiences in her “The Evidential Force of Religious Experience” (1989).  However, by being so broad, Swinburne’s five-fold definition drags less credible and subjective experiences into the discussion in a way that is not helpful when studying religious experience as a stand-alone topic or as evidence for the existence of God.  David Hume warned against relying on anybody who reports seeing a miracle in “Of Miracles” (1748), pointing out that it is impossible to know that the “miracle” is such (who can know the laws of nature sufficiently to know that an event breaks them, let alone that they have been broken “by particular volition of the deity or other invisible agent”?)  Further, says Hume, these witnesses lack credibility, being most often from “ignorant and barbarous nations” so having no relevant expertise and having plenty of bias and vested interests.  Take the miracle of the sun at Fatima in 1917; Hume would dismiss the many witness-reports as more likely to be based on the mistakes or lies of gullible or greedy people than genuine experiences of God.  While Swinburne rejects Hume’s argument using his Principles of Credulity and Testimony, both depend on our assessment of “prior probability”, which Swinburne suggests should be in favour of God existing and miracles possibly being genuine… because Religious Experiences are so common.  To be clear, Swinburne adopted his broad five-fold definition of Religious Experience in order to cast his net widely and include the experiences of as many people as possible, something that he needed to in the context of his wider probability argument for God’s existence which used the prevalence of religious experience to establish that it is more reasonable to assume that their object exists than not or what Swinburne calls “prior probability”.  At the same time, he rejected Hume’s warning against relying on reports of miracles because given our assessment of “prior probability”, the Principles of Credulity and Testimony dictate that we should believe both what we experience ourselves and what others tell us in terms of miracles and religious experiences in the absence of good reason not to.  There is a circularity here; Swinburne uses the prevalence of religious experiences in order to establish “prior probability” which he needs in order to establish the prevalence of religious experiences…  In this way, Swinburne’s broader definition is less useful than James’ narrower working definition because it includes less credible experiences which undermine religious experience as a topic and as possible evidence for God’s existence.   

In conclusion, James’ working definition of religious experience is the most useful for research into this topic.  James understood the pitfalls inherent in proposing any rigid definitions in this field and accepted that his working definition was not perfect.  He wrote: “The field of religion being as wide as this, it is manifestly impossible that I should pretend to cover it. My lectures must be limited to a fraction of the subject. And, although it would indeed be foolish to set up an abstract definition of religion’s essence, and then proceed to defend that definition against all comers, yet this need not prevent me from taking my own narrow view of what religion shall consist in for the purpose of these lectures…” p30  In this way, James’ four marks should be understood and used as indicators and tools to analyse experiences and not as necessary criteria.