Abstract

Many historians and philosophers of logic have claimed that during the modern classical era there was a long period of stagnation or even of decline in the field of logic. The aim of this paper is to convince the audience that this standard evaluation of the development of modern logic during the period from Leibniz to Frege is misdirected and needs to be corrected. Even though it is true that the now usual way of understanding logic merely as the doctrine of syntax and semantics of explicit languages would not have appealed even to most 19th century logicians, it is still not the case that there is nothing worth discussing with regard to the development of logic during the modern classical period. The algebraic period culminated with Schroder's contribution and neither Herbartian formal logic nor Trendelenburg's critical epistemology aroused much interest among the 20th century mathematical logicians and analytic philosophers. Nevertheless, the development of symbolic logic can only be understood properly by relating its emergence to the immediately preceding philosophically-oriented discussion about the reform of logic.