Under cover of the reasoning approached by Sigmund Freud Anatomy is destiny. The father of psychoanalysis thus expresses an analysis based on perfect objectivity. He seems to agree with the idea according to which the body would make itself command. However in this study it will be legitimate to appreciate the debates relative to trans-identitarians as questioning this scheme of thought. In the light of the perpetual evolution of the internal legal systems as well as their marked dissimilarity we will be able to identify a permanent heterogeneity. This will particularly formulate an element of discomfort with regard to private international law. Indeed the multiplicity of national rules generates the appearance of conflicts of laws and of complexities related to the exploitation of the rules inherent in private international law. It is agreed that private international law will be in charge of solving the difficulties raised by the discrepancies observed in domestic law. In this perspective it will be legitimate to wonder how private international law will be able to promote the recognition of the phenomenon of transidentity.