Dark Night of the Soul is one of the most important pieces of literature undergirding classical Christian mysticism. The phrase “dark night of the soul” has become, on a popular level, the description of a period of deep depression or dryness, but this is certainly not what St. John meant.
St. John was a Roman Catholic monk who lived from 1542-1591. He wrote his famous book in Spanish (this particular translation is by E. Allison Peers, published by Image Books in 1990). He set out, during the time of the Catholic Counter-Reformation, to explain the life of the mystic and the mystical way. Classical mysticism is composed of three parts: purgation, in which the senses and spirit are purged of all desires; illumination, in which God supernaturally floods the soul with His love while the individual remains passive; and union, in which the soul is united with God in perfection. Such an individual will be able to skip purgatory since purgatory’s work has been completed in this life (pp. 107-108, 174). To this pursuit the medieval monks and hermits devoted their lives.
The mystical way is nowhere supported by Scripture, even though St. John makes many attempts to do so. Yet mysticism has not only made a comeback in modern Catholicism, but is also all the rage in many evangelical circles, thanks largely to Richard Foster and his Celebration of Discipline.
Dark Night of the Soul is not a complete treatise on mysticism, focusing almost entirely on the first tier—purgation. It was apparently St. John’s intention to write on illumination and union, but either he chose not to do so or his manuscripts have been lost (p. 193).
Concerning purgation we are told that there is two stages: purgation of the senses (explained in book one) and of the spirit, the subject of book two. The dark night is a description of these two levels of purgation. In the first stage of purgation the senses and affections are killed in order that they not obstruct the spirit (pp. 73, 79, 85-87). Understanding needs to be brought into darkness and annihilated, in order that it can be informed passively concerning the Divine (pp. 121, 123, 146). Spiritual purgation, on the other hand, is the passive inflow of God secretly instructing the soul in perfection of love (p. 100). St. John writes,
For the spiritual and the sensual desires are put to sleep and mortified, so that they can experience nothing, either Divine or human; the affections of the soul are oppressed and constrained, so that they can neither move nor find support in anything; the imagination is bound and can make no useful reflection; the memory is gone; the understanding is in darkness, unable to understand anything; and hence the will likewise is arid and constrained and all the faculties are void and useless; and in addition to all this a thick and heavy cloud is upon the soul, keeping it in affliction, and, as it were, far away from God (p. 150).
This purgation ultimately leads to a union of love with God (pp. 158, 166, 191).
Those tempted to buy into the mystical revival within evangelicalism might want to read its foundational work. But do so with an open Bible for then it will become entirely clear that classical mysticism is not derived from the Word of God but from the imagination of men.