In the preface to the book by William Johnston, The Mysticism of the Cloud of Unknowing, Thomas Merton speaks about objections to apophatic mysticism, including the objection by those who are suspicious of “introversion.”
He says, “A final objection against apophatic mysticism will come from those who are suspicious of ‘introversion.’ This term was used by mystics before it was appropriated by modern clinical psychology. The introversion of the mystics is metaphysical rather than psychological, and rightly understood it has nothing to do with the introversion of narcissistic withdrawal. However the term is a bit misleading, and we must admit that there does exist a real danger of silent and passive contemplation becoming a mere exercise in narcissistic self-indulgence. One must not rest in the simple pleasure of one’s own being and become disinterested in other things, or in one’s necessary work. This too The Cloud explains sufficiently well. There is all the difference in the world between true contemplation and narcissistic repose in one’s own self. True contemplation results in greater freedom of action and indeed makes action more spontaneous, more loving, and more effective. Narcissistic withdrawal ends in confusion, laziness, self-concern, sensitivity and other such morbid effects. By their fruits you shall know them. (emphasis mine).
Johnston, William. The Mysticism of the Cloud of Unknowing. (2000, originally published in 1967). p. XVI.