ABSTRACT
Thalassa is a work that resulted from the exchanges between Sigmund Freud and Sandor Ferenczi concerning ontogenesis and phylogenesis. These exchanges emphasis to answer the questions that were raising in connection with the problem of the memory of the species and the transmission of the archaic experiences of humanity. The 'biological essay' in question is the outline of the book that Ferenczi published under the title Thalassa: A Theory of Genitality. On the occasion of its publication in Hungarian, five years after its original publication, Ferenczi modified the title of his book, calling it instead Catastrophes in the Development of the Genital Function: A Psychoanalytic Study. The leading idea of this book coincides with the thesis put forward by Freud in Beyond the Pleasure Principle concerning the 'conservative character of the instinct to restore an earlier state of things which the living entity has been obliged to abandon under the pressure of external disturbing forces'.
