This book investigates the core metaphysical problem of how objects persist through time and whether identity can be considered a temporary rather than an eternal state. André Gallois, a philosopher specializing in metaphysics, utilizes a rigorous analytical framework to challenge traditional views on persistence and change. By examining the logical structure of identity, he argues for the coherence of 'occasional identities,' suggesting that entities may be identical at one moment and distinct at another, thereby offering a novel resolution to classical philosophical paradoxes.

Experts recognize this work as a significant contribution to the literature on the metaphysics of time and identity. Readers frequently note the high level of technical rigor and the density of the prose, making it a text primarily suited for advanced students and professional philosophers.