Metalogic, Schopenhauer and Universal Logic

Schopenhauer used the word “metalogical” since his first work, On the Fourfold Root of the Principle of Sufficient Reason (1813), being the first to give it a precise meaning and a proper place within a philosophical system. One century later the word “Metalogic” started to be used and promoted in modern logic by the Russian logician Nicolai Vasiliev and the Polish School (Łukasiewicz, Tarski, Wajsberg). The aim of this paper is to examine the relations between the different uses of this word and doing that to try to have a better understanding of what Metalogic is and also logic tout court.