rapaport@cs.buffalo.EDU (William J. Rapaport) (11/20/87)
STATE UNIVERSITY OF NEW YORK AT BUFFALO BUFFALO LOGIC COLLOQUIUM COLIN McLARTY Department of Philosophy Case Western Reserve University NOTES TOWARD A NEW PHILOSOPHY OF LOGIC Today, logic is generally conceived as, more or less, describing pure laws of thought. But categorial logic has given an extensive, rigorous, formalized version of the claim that logic is simply the most abstracted aspect of concrete knowledge. In particular, different subject matters may have different logics. Categorial logic also urges a kind of structuralism: A subject matter (represented by a category) is seen as being determined by the relations to be considered among objects rather than by any specification of the individual constitutions of the objects. These points are illustrated by two examples. Differential geometry is one abstract representation of the world, one subject matter, with its own non-classical logic. Set theory is another, later, subject, with classical logic. I discuss the way set theory was derived from geometry in the 19th Century. Other philosophic applications of topos theory are based on the idea of a topos as a world in which truth varies over a range of viewpoints, which might be the situations of situation semantics or times in tense logic. All these considerations together argue that there is no one logic or one fundamental structure to the world. Wednesday, December 2, 1987 4:00 P.M. Diefendorf 8, Main Street Campus For further information, contact John Corcoran, (716) 636-2438.