Full Text

This article is a republication of a classic paper in which Rosenzweig introduced the concept of common factors in psychotherapy. This seminal idea—which refers to the finding that all forms of psychotherapy seem to share, to some degree, a small number of effective change ingredients—remains highly influential in psychotherapy integration today. Rosenzweig reviewed the data presented by then current forms of psychotherapy and argued that the theories that describe the change principles in each psychotherapy are inadequate to capture those deeper common factors.

“At last the Dodo said, ‘Everybody has won, and all must have prizes’.”

It has often been remarked upon that no form of psychotherapy is without cures to its credit. Proponents of psychoanalysis, treatment by persuasion, Christian Science and any number of other psychotherapeutic idealogies  ^{[  1  ]}  can point to notable successes. The implication of this fact is not, however, univocal. The proud proponent, having achieved success in the cases he mentions, implies, even when he does not say it, that his ideology is thus proved true, all others false. More detached observers, on the other hand, surveying the whole field tend, on logical grounds, to draw a very different conclusion. If such theoretically conflicting procedures, they reason, can lead to success, often even in similar cases, then therapeutic result is not a reliable guide to the validity of theory.

It takes but little reflection to arrive at the roots of the difficulty from the standpoint of logical deduction. Not only is it sound to believe that the same conclusion cannot follow from opposite premises but when such a contradiction appears, as seems to be true in the present instance, it is justifiable to wonder (1) whether the factorsalleged to be operating in a given therapy are identical with the factors that actually are operating, and (2) whether the factors that actually are operating in several different therapies may not have much more in common than have the factors alleged to be operating.

Pursuing this line of inquiry it is soon realized that besides the intentionally utilized methods and their consciously held theoretical foundations there are inevitably certain unrecognized factors in any therapeutic situation—factors that may be even more important than those being...