From Mechanism to Metaphor—on Freud's Struggle with the Biology of the Mind

One hundred years ago Sigmund Freud, a young neurologist, set an ambitious goal for himself. He spelled out his goal in the opening sentence of his posthumously published Project for a Scientific Psychology (1895): “The intention is to furnish a psychology that shall be a natural science: that is, to represent psychical processes as quantitatively determinate states of specifiable material particles” (p. 295). Like so many others before and after him, Freud did not achieve this goal. Instead, he turned his attention to psychic entities themselves—their development, interrelations, and pathology. In doing so he moved further and further away from biology. Freud the psychoanalyst never quite gave up the youthful ambition of Freud the neurologist, however. Likewise, he never fully abandoned his neurobiological language and imagery. References to biology permeate Freud's psychological work throughout his life. They appear both in the form of essential, evolving currents that were central to his thinking (as in his “energy” theory and his notion of “quantity”), as well as in the form of isolated references that crop up, sometimes unexpectedly, in his later writings. In this article I attempt to trace a few of the references to biology that are scattered throughout Freud's psychological writings and use them to follow the evolution of his views about and his struggle with the biology of the mind.

A discussion of Freud's view of the mind—body problem is crucial to understanding his search for a biology of the mind. The mind—body problem, one of the central, enduring dilemmas in Western philosophy, cast its long shadow on Freud's metapsychology, as it does today on contemporary neurobiological and psychoanalytic theories. Freud's understanding of the mind—body problem before he began to focus on