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
Peter Thomas Geach (29 March 1916 – 21 December 2013) was a British philosopher who was Professor of Logic at the University of Leeds. His areas of interest were philosophical logic, ethics, history of philosophy, philosophy of religion and t ...
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
, mottoeng = Literal: From here, light and sacred draughts.
Non literal: From this place, we gain enlightenment and precious knowledge.
, established =
, other_name = The Chancellor, Masters and Schola ...
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, ar ...
and
J. M. E. McTaggart 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
The B-theory of time, also called the "tenseless theory of time", is one of two positions regarding the temporal ordering of events in the philosophy of time. B-theorists argue that the flow of time is only a subjective illusion of human consciousn ...
References
Concepts in logic
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