The idea of decathexis, or withdrawal of cathexis, is linked to the notion of psychic energy and occurs very early on in Freud's work, although the term itself or its equivalents are not explicitly used. As early as "The Neuro-Psychoses of Defence" (1894a), Freud outlines certain mechanisms for repressing representations when he writes that we have "an approximate fulfillment of the task if the ego succeeds in turning this powerful idea into a weak one, in robbing it of the affec, the sum of excitation with which it is loaded" (1894a, p. 48). In fact the notion of decathexis first appears as a means of repression in his work on the paranoia of Justice Schreber: "It is quite possible that a detachment of the libido is the essential and regular mechanism of every repression" (1911c [1910], p. 71). But the important role eventually attributed to energy in the very constitution of the psyche would make decathexis a central notion, independent of the mechanism of repression. The nature of decathected mental structures or objects, the more or less massive modalities of the decathexis, and the fate of the withdrawn energy, all would have serious consequences. As Freud writes: "the liberated libido will be kept in suspension within his mind, and will there give rise to tensions and color his mood" (1911c [1910], p. 72), until it finds another attachment. In the case of paranoia it will hypercathect the ego.- International Dictionary of Psychoanalysis, ©2005 Gale Cengage.
Ah si`, il discorso sulla libido liberata si traduce, in parole semplici, in "ma trombare"?

Gia`, appunto. Eppure ci dovrebbero essere anche modi meno terra-terra di usare l'energia.