In his preface to the book with which we shall be concerned here the author describes his work as a textbook for those students of the humanities who are preparing for the examination in "the principles of philosophy", which is obligatory for all those candidates for the degree of Master of Arts in Polish universities who do not take philosophy as their principal subject. He also thinks that it may serve as a textbook for those who are to sit for an examination in logic, methodology and epistemology, obligatory for those who major in philosophy and pedagogy. This presentation of the work as a textbook may give rise to a bias against its scientific value, since textbooks usually are compilations, expositions of things already accepted, and as a rule do not contribute much new to science. In the present case, although the work is called a textbook, it is not merely that. Professor Kotarbiński's book comprises a wealth of tersely formulated original opinions which would suffice to fill a number of monographs. To Polish culture it contributes new values, not only didactic, but also scientific.