This article comments on the Freudian distinction between sexuality, as an observable fact, and libido, as a speculative hypothesis, demonstrating that, for Freud, the supposition of a specific energy for sexual drive corresponds to a concept that has only instrumental - or heuristic - validity rather than an objective empirical reference. It is also pointed out that Freud does not consider the concepts of this type - speculative - to be the basis of his science, but the replaceable apogee of the theoretical edifice of psychoanalysis. This type of interpretation of Freud's work,, which integrates it in the history of German philosophy and science, permits not only the comprehension of psychoanalysis as a science from a heuristic perspective but also makes possible an analysis of the developments of psychoanalysis that takes into account the difference between empirical and theoretical (speculative) data, explaining in what sense the psychoanalytical theory is considered by Freud as provisional and always open to revisions.
Sexuality; libido; speculation; heuristic; psychoanalysis