MYSTICAL EXPERIENCE
The "Principle of Causal Indifference"
In response to those who tend to confuse their own cultural tendencies and religious dogmas with universal, absolute and eternally valid configurations, I contribute with a translation of some pages written by Stace, W. T. in "Mysticism and Philosophy" — Philadelphia: J. B. Lippincott (1960), regarding a discussion about the value of psychedelic substances as instruments of spiritual opening.
Extract
The "Principle of Causal Indifference" is the following: If "X" has an alleged mystical experience called "P1" and "Y" in turn has an alleged mystical experience called "P2", and if the phenomenological characteristics of "P1" entirely resemble the phenomenological characteristics of "P2", as far as can be ascertained by the descriptions given by "X" and "Y", then the two experiences cannot be considered different or of two types — for example, we cannot say that one of them is a 'genuine' mystical experience and the other is not — simply because they arise from different causal conditions.
The principle seems logical and obvious, although it may not be very important at the moment and have no well-defined practical application, but it may become important in the future. Such a principle is introduced here because it is occasionally claimed that mystical experiences can be induced by chemicals, such as mescaline, lysergic acid, etc. On the other side, those who have attained mystical states resulting from long and arduous spiritual exercises, such as fasts and prayers, or great moral efforts, possibly sustained over many years, are inclined to deny that a chemical substance is capable of inducing a "genuine mystical experience", or at least to look with suspicion upon such practice and claim.
Our principle says that if the phenomenological descriptions of the two experiences are indistinguishable, as far as can be ascertained, then it cannot be denied that, if one of them is a genuine mystical experience, the other must also be. This follows despite the modest antecedents of one of them, and despite the possible and understandable annoyance of an ascetic, a saint, or a spiritual hero, who is told that a worldly and negligent neighbor, apparently doing nothing to deserve such an achievement, attained mystical consciousness by swallowing a pill. (pages 29–30).
Another application of our principle, which may be cited, arises in relation to the second of the three famous periods of mystical illumination in the life of Jakob Boehme. This second illumination is described as having been induced in the contemplation of a polished disc. Now, looking at a simple polished surface seems, in the same way as before, somewhat modest and unspiritual as a causal condition for a mystical experience; nevertheless, no one, I imagine, will deny the fact that Jakob Boehme was a "genuine mystic". (Pages 30–31)
Those who think it impossible that an experience with Mescaline could be mystical and genuine, even if indistinguishable from the phenomenological standpoint, may also consider the fact that the contemplation of a "flowing stream of water" caused Saint Ignatius of Loyola to attain a manifest state of mystical consciousness in which he "came to understand spiritual things". (page 70). Stace, W. T. in "Mysticism and Philosophy"