In Epicurean cosmology, material reconstitution, or palingenesis (παλιγγενεσία) is the necessary consequence of the infinity of time and the eternity of atoms. I examine Lucretius’ treatment of this phenomenon (DRN 3.843–864) and consider the extent to which his view enables us to develop an Epicurean response to the question: what makes a person at two different times one and the same person? I offer a reading of this passage in the light of modern accounts of persistence and identity, and what (...) Lucretius states in Books 3 and 4 about memory and the soul’s motions. Guided by the metaphysical implications of this analysis, I determine the type of relation which, according to Lucretius, holds between the mental and the physical. (shrink)