Instincts and homeostasis

In an objective re-evaluation of the concept of instinct, the author supports two of Freud’s largely neglected contributions that instincts must be classified on a physiological rather than on a psychological basis and that they represent a demand made by the body on the mental apparatus. No absolute distinctions can be made between instincts and drives; differences are rather quantitative than qualitative. Instincts can be arranged in a hierarchy “from a preponderance of biochemical influences on the neuronal pattern to a preponderance of psychologic influence.”