Abstract
ARTHUR PRIOR once wrote that "philosophical discussion of the notion of existence, or being, has centred on two main problems...." One of them was the problem of what to say about the existence of fictitious objects, and the other the problem of what to say about abstract objects. Historically, however, this claim is hardly correct; for the existence of individuals that are real rather than fictitious, and concrete rather than abstract, has been at least as central a topic as those mentioned by Prior. It is with the existence of such individuals that I shall be concerned in this paper.