 What are the connections between Collins’ account of emergent properties and his account of personal identity? The most important connection is the Lockean distinction between the matter that composes a material thing at any given time and the organization of matter. The distinction comes from Locke’s account of the individuation of masses of matter and living things in his chapter “Of Identity and Diversity” in Book II of the Essay Concerning Human Understanding. A mass of matter is individuated by the particles that compose it, however organized. If the mass gains or loses a single particle it becomes a different substance. Living things, by contrast, are individuated by their functional organization (Locke 1690: II. xxvii 3 [1975: 330). Collins’ summary of his views on identity and personal identity make it clear that he agrees almost completely with Locke’s account of identity and the individuation of masses, living things and persons (Clarke 1738 [1928: 875]; Clarke and Collins 2011: 231–232). But Clarke insists that in order for something to remain the same, it must remain the same substance. In the case of material things like oaks, this means that the matter that composes it must remain the same or it is not the same oak. Only atoms, souls and God fulfill this same substance condition for Clarke. So, oaks are only identical in a fictional sense. In addition, it is not possible for any entity to have the same properties it had previously if its substance has changed, because it is not possible to transfer properties from one substance to another (Clarke 1738 [1928: 798]; Clarke and Collins 2011: 113). So, just as Clarke holds that emergent properties are fictional, so he holds that any identity not based on identity of substance is fictional. The clash between the two over the metaphysical importance of organization is fundamental to their different views of emergent properties, identity, and personal identity.