The Fallacious Use of Quantitative Concepts in Dynamic Psychology

A system of psychological concepts merits being called 'dynamic' when it comprehends conscious and unconscious motivations, and when it can demonstrate how the interaction between various psychological states can play an active rôle in determining the course of human life. In any effort to formulate a system of dynamic psychology it is difficult to be sure when our words describe and when they explain. Indeed the boundary lines between description and explanation are never sharp in science. Many constant sequences are found to have cause-and-effect relationships, and many apparent cause-and-effect relationships turn out to be mere coincidental sequences. In the effort to deal with this difficulty, there is a tendency in psychology to fall back largely on quantitative concepts, that is, on the explicit or implicit assumption that a change in dimension or volume or size or strength in one or another component of the total psychological constellation is the effective variable which causes all other changes. There are some dangers in this type of formulation.

Let me begin with a quotation from page 313 of Freud's Introductory Lectures on Psychoanalysis (4). This was written before 1920 when the introduction of the structural viewpoint brought far-reaching changes into psychoanalytic theory. Nevertheless the quantitative assumptions of the earlier theories were carried over without re-examination into the structural era of psychoanalytic theory.

You will doubtless have noticed that in these last remarks I have introduced a new factor into the concatenation of the ætiological chain—namely, the quantity, the magnitude of the energies concerned; we must always take this factor into account as well. A purely qualitative analysis of the ætiological