Memory and St. John of the Cross

In the Ascent of Mount Carmel, St. John of the Cross prepares advancing souls for the gift of God. In his treatise on memory, found in the third book of the Ascent, he teaches that there must be a void in order to make a place for God. This void is often referred to as “nakedness of spirit”.
“In each of these books readers must keep in mind the intention we have in writing. Failure to do so will give rise to many doubts about what they read. They may already have them concerning the instructions given for the intellect, or they may experience them on reading what we say about the memory and the will.” 
“Observing how we annihilate the faculties in their operations, it will perhaps seem that we are tearing down rather than building up the way of spiritual exercise. This would be true if our doctrine here were destined merely for beginners who need to prepare themselves by means of these discursive apprehensions.” 
“But we are imparting instructions here for advancing in contemplation to union with God.”

Souls advancing along the way in prayer toward union need to keep in mind that God operates the union. There is only one way to allow Him to do it, that is, to make the void which forces the powers, in this case, the memory, to deny its natural operation. Once there is a void in the memory a place can be given to God and to the supernatural infusion.
St. John instructs souls in a method they will need to apply to the memory in order to leave it empty. It is done by changing its habits. Firstly, its habits are changed by putting a bound to its limits- constraining its power. All this is so that it can be elevated above itself, elevated above all distinct knowledge and above all it possesses in order to place it in Hope.
“To begin with natural knowledge in the memory, I include under this heading all that can be formed from the objects of the five corporeal senses (hearing, sight, smell, taste, and touch), and everything like this sensory knowledge that the memory can evoke and fashion, It must strip and empty itself of all this knowledge and these forms and strive to lose the imaginative apprehensions of them. It should do this in such a way that no knowledge or trace of them remains in it; rather it should be bare and clear, as though nothing passed through it, forgetful of all and suspended.” (Ascent of Mount Carmel Book 3, chapter 2)
Keep in mind that for St. John of the Cross the memory is a repository of forms that were received through the fives senses. The soul takes this sensory information, along with the work of the imagination, and is able to synthesize these forms into more and various ways to produce still other forms with which the soul is not directly familiar. Given then the nature of this faculty and its ability to synthesize new material to present to the intellect and will, it is imperative that all principles involved in the negation that St. John proposes need to be applied before union can take place. The reason is clear for this negation. God is Spirit and is contrary to nature. For the soul to be transformed, the memory, as well as the intellect and will, must be stripped of its own natural activity in order to enter into union with God.