Kazimierz Twardowski (1866-1938) is the founder of the Lvov-Warsaw School with its strong tradition in logic and its scientific approach to philosophy. Twardowski's unique way of doing philosophy, his method, is of central importance for understanding his impact as a teacher. This method can be understood as a philosophical grammar, which is also how Leibniz conceived his universal language of thought. Analytic philosophy in the twentieth century can be characterized by its opposition to psychologism, on the one hand, and its opposition to metaphysics, on the other. This is changing now, as...