The expression reciprocal paths of influence refers to routes that lead from a nonsexual function to a sexual function, but that can be traversed in both directions.
In Three Essays on the Theory of Sexuality (1905d) Sigmund Freud added to the somatic sources of sexual excitation (erotogenic zones) other sources that are unlimited in number, since they involve any internal process that has surpassed a certain quantitative threshold.
Two aspects of this notion of reciprocal paths of influence must be distinguished.
This hypothesis is extremely important because it makes it possible simultaneously to account for sublimation (attraction of the sexual toward the nonsexual) and symptom formation (attraction of the nonsexual toward the sexual). In fact, it considerably broadens the notion of sexuality to encompass the notion of "pleasure in thinking," a very different perspective from the one that equates thinking with labor.
Bibliography
Freud, Sigmund. (1905d). Three essays on the theory of Sexuality. SE, 7: 123-243.
Laplanche, Jean. (1976). Life and death in psychoanalysis. Baltimore, MD: Johns Hopkins University Press.
Mijolla-Mellor, Sophie de. (1992). Le Plaisir de pensée. Paris: Presses Universitaires de France.
—SOPHIEDE MIJOLLA-MELLOR