Kazimierz Jerzy Skrzypna-Twardowski was a Polish philosopher, psychologist, logician, and rector of the Lwów University. He was initially affiliated with Alexius Meinong's Graz School of object theory.
Kazimierz Zalewski, pseudonym Jerzy Myriel, was a Polish dramatist, literary and theatre critic, one of the leading author of middle-class positivistic drama.
Kazimir Severinovich Malevich was a Russian avant-garde artist and art theorist, whose pioneering work and writing influenced the development of abstract art in the 20th century. He was born in Kiev, to an ethnic Polish family. His concept of Suprematism sought to develop a form of expression that moved as far as possible from the world of natural forms (objectivity) and subject matter in order to access "the supremacy of pure feeling" and spirituality. Malevich is also sometimes considered to be part of the Ukrainian avant-garde that was shaped by Ukrainian-born artists who worked first in Ukraine and later over a geographical span between Europe and America.