The purpose of this dissertation is to examine the relationship between Locke\u27s anti-essentialism and his theory of identity. Subsequent to developing these theories in chapters one and two, I argue that the organisms and persons in Locke\u27s ontology must have both spatial and temporal extent, since he takes them to be diachronically compounded out of shorter-lived, successively existing substances. In chapter four I defend this interpretation by arguing, first, that Locke could have entertained a four-dimensional account of physical objects, and hence that this interpretation of his identity chapter is no mere anachronism. I subsequently present some additional reasons for thinking that he would be favorably disposed towards such an a...