Repetition should be distinguished from regression. Regression is the psychical counterpart of the second thermodynamic law (Entropiestreben), law of entropy. Repetition is the exact opposite, to the tendency, in the above law. Its psychical counterpart is instinct. These two opposing forces, i.e. repetition and regression, are a dualism which is a primary biological phenomenon. The postulation of a death instinct is in no way necessary to explain aggressivity. It may rather be explained in the same way as sexual orgasm, as a method of increasing the individual's entity (zur Steigerung des eigenen Daseins). This desire for the increase of entity may become so potent that it excludes all other interests, even that of self-preservation. Sublimation is one aspect of this desire.