Abstract
Kazimierz Ajdukiewicz is known primarily as a logician and methodologist. Ethics was a side discipline to his scientific research, which he lectured at Lvov University in the 1930s. Assuming that ethics is a philosophical science, he tried to systematise its contemplations according to the scientific principles developed at the Lvov–Warsaw School of thought. However, in his research he also took into account the philosophical tradition which recognised ethics as one of the chief branches of philosophy. Ajdukiewicz’s submission of ethics to the requirements of logic was related to an attempt to analyse its core concepts. Consequently, an outline of the original ethical concept was developed, but never developed into a system.