Pupil of Brentano, and founder of the Lvov-Warsaw School of philosophy and logic. Twardowski studied in Vienna, and was appointed professor at Lvov in 1895. His charismatic teaching helped to inspire a generation of students, including Kotarbinski, Łukasiewicz and Lesniewski. The philosophy of the Lvov-Warsaw school was that ‘vera philosophiae methodus nulla alia nisi scientiae naturalis est’, a motto taken from Brentano (the method of true philosophy is nothing other than that of natural science); later this meant an extraordinarily fruitful alliance with formal logic, which culminated in the work of Tarski.