The paper presents the academic personality of Kazimierz Twardowski (1866-1938). Twardowski was born and educated in Vienna, where he was a student of Franz Brentano. After achieving habilitation, he moved to Lvov, where he organized serious philosophical research and became the founder of the Lvov-Warsaw School of philosophy and logic. The Twardowski's achievements in three dimensions: as a teacher, as an organizer and as a scientist are briefly described.