  Next Reid considers a theory he associates with Locke, namely that universals do not exist as metaphysical forms but rather universals are abstract ideas. Abstract ideas arise through a process in which facts about time and space are stripped away from particular members of a class of thing leaving the abstract idea that represents common characteristics (EIP 3.2). Reid argues that there can be no such abstract ideas and that abstract ideas cannot represent members of a class of particulars (EIP 5.6, 391–3). Reid recognizes his great debt to Berkeley's criticisms of Lockean abstract ideas in these connections.