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On the Reality of Existence and Identity

Published online by Cambridge University Press:  01 January 2020

Ian Hacking
Ian Hacking*
Affiliation:
Stanford University
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Extract

“The confusion of a logical with a real predicate,” according to the Critique of Pure Reason, “is almost beyond correction” (A598/B626). Kant did not assert that existence is no predicate, but that it is only a “logical” one, and not a “real” one. Much the same thing has been said about identity, although Kant himself thought it is real and not logical. We have long lacked a rigorous criterion to distinguish real from logical predicates, and hence have not been able to say why the difference matters. This paper has two objects. First it provides a demarcation between real and logical predicates that confirms Kant's dictum that existence is only “logical.” Secondly it states the theory of a “logical” (but not “real”) relation of identity. Perhaps this is not the only identity relation. I show only that once it has been precisely defined in the right setting, there are definite answers to a number of disputed questions about identity. Maybe there are other concepts of identity for which different answers are to be given, but I shall not discuss that disagreeable prospect here. A third application concerns the ontological argument.

Type
Research Article
Information
Canadian Journal of Philosophy , Volume 8 , Issue 4 , December 1978 , pp. 613 - 632
Copyright
Copyright © The Authors 1978

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