Abstract
To tackle a legal problem, you first need concepts to make it manageable, then solve it in the light of value criteria deemed preferable. The jurist P. Alfenus Varus, consul in 39 BC and a leading figure on the Roman political and cultural scene, had to determine whether changing a few judges on a jury altered the identity of the jury and the trial (Digest, 5.1.76). A question of identity over time, then. How to deal with it ? Alfenus uses the notion of bodies developed by Greek philosophy, which distinguishes them according to whether they are unitary (like a stone), composed of coherent elements (like a ship) or of separate elements, but conceptually considered as a single body (like a people). Behind this question lie profound philosophical dilemmas, such as the one represented by Theseus' ship or, even more troubling, the one concerning the identity in time of each and every one of us. Can we be considered the same as we were a week ago, despite the incessant changes in our physical make-up ? The idea of the body serves not only to produce metaphors for naming concepts, but also as a tool for argumentation.
