This paper is an attempt to formulate more exactly the concept of the essence of neurosis which Kubie has approached in many previous writings. His idea is that a nuclear, as opposed to a holistic, definition is possible. He finds this possibility in the type of determination of any individual act of behaviour or mentation. In so far as the alliance of conscious and preconscious mental systems is dominant the act is normal; in so far as unconscious determination is dominant it is neurotic. This must be so because domination by the conscious-preconscious alliance means the possibility of flexibility of response, whilst domination by unconscious motivation implies domination by unmodifiable repetitive responses. It is just this rigidity of response which characterizes the neurotic process.

Kubie deals in detail with numerous misunderstandings and criticisms of his theory.