## RESUMO / ABSTRACT

Abril 1997

**Bernhard Banaschewski**, McMaster University (Hamilton)

*The Algebra of Boole's logic*

This is an analysis of the laws which are explicitly stated in Boole's "Laws of Thought", showing that the mathematical systems they determine are actually very far from Boolean algebras but reduce to the latter when the Law of the Excluded Middle, or some similar principle, is added - which Boole, somewhat curiously, did not specifically list.