In order to assess the tenacity of psychoanalysts in continuing to use a concept of psychic energy, it is advisable to consider whether, as they sometimes claim, the concepts of energy, force, and work in psychoanalysis are akin to those in the natural sciences. Strong disanalogies suggest that the psychoanalytic concepts are quite different and used equivocally even within psychoanalysis. However, they may not be subject to the objections which certain critical psychoanalysts have raised.