THE setting free of Poland after the First World War W3:S fol- lowed by intensive activity in her Universities. In the depart-
ments of philosophy and mathematics this took the form, in a
number of places, of new and powerful investigations in the
fields of mathematical logic, the foundations of mathematics,
and the methodology of the sciences. Prominent in this move-
ment was the Warsaw school led by Lrurasiewioz, Kotarbmski,
and Lesniewski. Under their skilled guidance a younger genera-
tion grew up and among these Alfred Tarski quickly dis-
tinguished himself.