A Cambridge change occurs when a predicate P is true of object O at this moment (Chicago is ''north of me'') but is not true of O the next moment (Chicago is ''south of me''), not because O's bodily constitution is no longer the same, but because some difference in the constitution of an object G (I have moved from Atlanta to Toronto) makes logically necessary the passage of the original predicate from true to not true.
History
The term ''Cambridge change'' was coined by
Peter Geach in the late 1960s
[Geach, P.T. (1969). ''God and the Soul''. London: Routledge.][Change]
. ''Stanford Encyclopedia of Philosophy''. Retrieved on 2009-10-16. because the influential
Cambridge University
The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209 and granted a royal charter by Henry III of England, Henry III in 1231, Cambridge is the world' ...
philosophers
Bertrand Russell
Bertrand Arthur William Russell, 3rd Earl Russell, (18 May 1872 – 2 February 1970) was a British mathematician, philosopher, logician, and public intellectual. He had a considerable influence on mathematics, logic, set theory, linguistics, ...
and
J. M. E. McTaggart
John McTaggart Ellis McTaggart (3 September 1866 – 18 January 1925) was an English idealist metaphysician. For most of his life McTaggart was a fellow and lecturer in philosophy at Trinity College, Cambridge. He was an exponent of the phi ...
used examples of such changes in their work.
Example
Last year Mary, who stands five-foot-four, was taller than her five-foot tall, 13-year-old son John; today Mary is shorter than her now five-foot-six, 14-year-old son. Mary has undergone a Cambridge change.
The Cambridge change that Mary has undergone consists in the fact that a predicate true of her last year (''taller than John'') is not true now, and a predicate not true of her last year (''shorter than John'') is now true; but the change in the predicates’ truth values is not grounded in any change in her height. By contrast, the change in the truth value of last year's and this year's statement about John's height reflects his growth.
Some philosophers have proposed that a Cambridge change is a change in an individual's
extrinsic
In science and engineering, an intrinsic property is a property of a specified subject that exists itself or within the subject. An extrinsic property is not essential or inherent to the subject that is being characterized. For example, mass ...
or relational properties; genuine changes involve
intrinsic
In science and engineering, an intrinsic property is a property of a specified subject that exists itself or within the subject. An extrinsic property is not essential or inherent to the subject that is being characterized. For example, mass ...
ones.
See also
*
Russellian change
References
Concepts in logic
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