Abstract

Stanislaw Lesniewski is called a nominalist, even though his published works contain no developed philosophical doctrine. Yet, in order to understand and interpret his logical systems, we must understand his nominalism. This thesis will investigate, in detail, the philosophical origins of the "nominalistic" elements of Lesniewski’s logical systems and will offer a characterization of his nominalism. This thesis will provide a brief historical sketch of Lesniewski 1s career as a logician and of the times in which his logical systems were developed. A definition of nominalism will be developed within the context of the realist/nominalist debate over the existence of universals and a realists notion of universals will be given as a background against which Lesniewski's philosophical beliefs can be measured. The philosophical origins of Lesniewski's nominalism will be explored and will provide the basis for an examination of the nominalistic elements of his logical systems and the basis for a characterization of his nominalism. Lesniewski's nominalism avoids traditional classification and can only be examined indirectly through an analysis of his logical systems and through his attitude towards Russellian classes. In the final analysis, it is best to say that Lesniewski was a philosopher who created consistent logical systems in which to "talk" about objects.