Abstract
In this paper, we present a logical system which is constructed on the following principles: I) the singular proposition is a universal proposition with a singular term as its subject; II) the identity proposition is a singular proposition with a singular term as its predicate; III) a singular term is a term which designates the only one object. The resulting system is shown to be inferentially equivalent to the original system of Lesniewski's Ontology dating from 1920. We shall present some results on the comprehension axiom and the law of extensionality, too.
