Abstract

I want to show that Leibnizian mode to thinking is based in a kind of logic of concepts. As an example, his first attempt to sum infinite series is analyzed. The question concerning the justification of the Leibnizian syllogism leads to the analysis of the fundamental definition. A conclusion obtained by “real-definitions” (“Realdefinitionen”) is logically justified. It is classified as a "Vernunftwahrheit". A conclusion obtained by paradoxical definitions (paradoxe Definitionen) is classified as a “Tatsachenwahrheit”. According to Leibniz it has validity by contingency. A conclusion obtained by “impossible definitions” is logically unjustified