ABSTRACT
Regression and reactive alteration of the ego, isolation and “undoing” what has been done are all cited as defensive techniques employed in obsessional neurosis. Methods such as that of isolation and undoing stand side by side with genuine instinctual processes, such as regression, reversal, and turning against the self. Repression is preeminently of value in combating sexual wishes, while other methods can more readily be employed against instinctual forces of a different kind, in particular, against aggressive impulses. Or these other methods have only to complete what repression has left undone or to deal with such prohibited ideas as return to consciousness when repression fails. Or possibly each defense mechanism is first evolved in order to master some specific instinctual urge and so is associated with a particular phase of infantile development. A classification of the defense mechanisms according to position in time inevitably partakes of all the doubt and uncertainty which even today attach to chronological pronouncements in analysis.
