Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-15T02:24:13.360Z Has data issue: false hasContentIssue false
  • English
  • Français

On the Reality of Existence and Identity

Published online by Cambridge University Press:  01 January 2020

Ian Hacking
Ian Hacking*
Affiliation:
Stanford University
Get access Rights & Permissions [Opens in a new window]

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Barcan, Ruth C. “The Identity of Indiscernibles in a Strict Functional Calculus of Second Order.” Journal of Symbolic Logic 12 (1947), pp. 12–15.CrossRefGoogle Scholar
2. Church, Alonzo Introduction to Mathematical Logic, Sec. 58. Princeton, 1956.Google Scholar
3. Descartes. Philosophical Writings. Translated and edited by Anscombe, G. E. M. and Geach, P. T. The Open University, 1970. P. 105.Google Scholar
4. Geach, P. T. Reference and Generality. Cornell, 1962. P. 39.Google Scholar
5. The Collected Papers of Gerhardt Gentzen, Translated and edited by Szabo, M. E. Amsterdam, 1969. No.3.Google Scholar
6. Hacking, Ian “The Identity of Indiscernibles.” Journal of Philosophy 62 (1975), pp. 249-56.CrossRefGoogle Scholar
7. Hacking, Ian “Do-it-yourself Semantics for Classical Sequent Calculi, Including Ramified Type Theory.” In Logic Foundations of Mathematics and Computability Theory, edited by Butts, R. and Hintikka, J. pp. 371-90. Dordrecht and Boston, 1977.CrossRefGoogle Scholar
8. Hacking, Ian “What is logic?” Journal of Philosophy, in press.Google Scholar
9. Hacking, Ian “Comment.” In Philosophy of Logic, edited by Korner, S. pp. 147-59. Oxford and California 1976.Google Scholar
10. Hintikka, Jaakko “On the logic of Existence and Identity.” Monist 50 (1950), pp. 55–76.CrossRefGoogle Scholar
11. Hintikka, Jaakko. Logic, Language Games and Information. Oxford, 1973.Google Scholar
12. Kneale, W. C. “The Province of Logic.” In Contemporary British Philosophy, 3rd series, ed. Lewis, H. D. pp. 235-61. Aberdeen, 1956.Google Scholar
13. Kripke, Saul “Identity and Necessity.” In Identity and Individuation, edited by Munitz, M. K. New York, 1971.Google Scholar
14. Kripke, Saul “Substitutional Identity.” In Truth and Meaning, edited by Evans, G. and McDowell, J. Oxford 1976. P. 368.Google Scholar
15. Lorenzen, Paul Einfuhrung in die Operative Logik und Mathematik. Berlin, 1955.CrossRefGoogle Scholar
16. Moore, G. E. “Is Existence a Predicate?” (1936) In Philosophical Papers, pp. 115-26. London, 1959.Google Scholar
17. Perry, John “The Same F.” Philosophical Review 79 (1970), pp. 181–200.CrossRefGoogle Scholar
18. Popper, K. R. References in The Philosophy of Karl Popper, edited by Schillp, P. vol. 1. La Salle, III., 1974. P. 100.Google Scholar
19. Prawitz, Dag Natural Deduction. Stockholm, 1965.Google Scholar
20. Ramsey, F. P. The Foundations of Mathematics and Other Logical Essays. London, 1931. Pp. 29–32.Google Scholar
21. Smiley, T. J. “Sense without Denotation.” Analysis 20 (1960-61), pp. 125-35.CrossRefGoogle Scholar
22. Whitehead, A. N. and Russell, B. A. W. Principia Mathematica, 2d ed. Cambridge, 1925. Vol. 1.Google Scholar
23. Wiggins, David “Identity, Necessity and Physicalism.” In Philosophy of Logic, edited by Korner, S. Oxford and California, 1976. P. 164.Google Scholar