 In the well known work What is Philosophy? Bolzano elucidated his concept of philosophy and of philosophizing and put forward his view of the task of philosophy (Bolzano 1849a). Philosophizing is not restricted to a certain area of knowledge, according to Bolzano. As soon as you ask for reasons, you are philosophizing, and this can be done in any discipline, also outside of the genuine fields of philosophy. Bolzano does not conclude from this, however, as later Ludwig Wittgenstein, Moritz Schlick and Rudolf Carnap did, that there is no proper realm of philosophical problems and philosophical subject matters. Quite to the contrary, he adhered to the traditional division of philosophy into subdisciplines according to the different subject matters that are concerned.