"Psychological development "is a matter or self understanding, self acceptance, and personal integration. The former (mystical path) involves itself with self-forgetting, the disappearance of the self into mysterious union with God, Absolute, the Transcendent aspect of reality, the Tao. Thus the term self-transcendent (with emphasis on the small "s" self in the self, as opposed to the Self, higher aspect of the personality) means letting go of egoistic interests and practical, worldly matters."
Sinetar - Ordinary People as Monks and Mystics.
"Mystical science is for those who can obtain satisfaction of their worldly need from appropriate sources and do not seek them, in disguise, in the spiritual domain. Worldly need must be satisfied elsewhere so that their pursuit does not interfere with there learning process. Similarly, psychopathology must be dealt with first. Consequently there is no way for mysticism to substitute for psychotherapy, or visa versa."
Deikman - The Observing Self
But you have to be somebody before you can be nobody. The issue in personal development as I have come to understand it is not self or no-self, but self and no-self. Both a sense of self and insight into the ultimate illusoriness of its apparent continuity and substantiality are necessary achievements. Sanity and complete psychological well-being include both, but in a phase-appropriate developmental sequence at different stages of object relations development. The attempt to bypass the developmental tasks of identity formation and object constancy through a misguided spiritual attempt to "annihilate the ego" has fateful and pathological consequences. This is what many students who are drawn to meditation practice and even some teachers seem to be attempting to do.
Jack Engler - Transformations of Consciousness
What Buddhist psychology and practice appear to do instead is presuppose a more or less normal course of development and an intact or "normal" ego.
Jack Engler - Transformations of Conscious