Freud

"That this is a philosopher's study of Freud may be apparent from a certain unworldliness in the face of questions of energy. With the general aim of expounding an extolling Freud's theories, Wollheim makes a dutiful nod to physics in this passage, but otherwise quite uncritically recounts the rather un-physical behaviour of energy in the mind: "there is energy or quantity, known as Q, whose flow through this network [of neurons] is governed by the laws of physical motion. The working principle of this model is that of 'neurotic inertia', or the Constancy Principle, according to which the apparatus has a tendency to divest itself of energy, or to reduce tension, where tension is identified with the accumulation of energy. From the Constancy Principle we can, however, immediately infer a difference within the neurones, between sensory neurones, which receive stimulation, and motor neurones, which control movement or action. For energy arises from stimuli and it is got rid of, or discharged, through motor activity, of which the preferred form is flight." (p.45) We are apparently to suppose that the energy for flight, the "preferred form" (?) of motor activity, is derived from stimuli, rather than, say, food.