of cognition. Thus, natural knowledge makes strides. It progressively takes possession of a reality at first existing for us as a matter of course and as something to be investigated further as regards its extent and content, its elements, its relations and laws. Thus the various sciences of the natural sort (naturlichen Wissenschaften) come into being and flourish, the natural sciences (Naturwissenschaften) as the sciences of physics and psychology, the sciences of culture (Geisteswissenschaften) and, on the other side, the mathematical sciences, the sciences of numbers, classes, relations, etc. The latter sciences deal not with actual but rather with ideal objects; they deal with what is valid per se, and for the rest with what are from the first unquestionable possibilities. In every step of natural cognition pertaining to the sciences of the natural sort, difficulties arise and are resolved, either by pure logic or by appeal to facts, on the basis of motives or reasons which lie in the things themselves and which, as it were, come from things in the form of requirements that they themselves make on our thinking. Now let, us contrast the natural mode (or habit) of reflection with the philosophical. With the awakening of reflection about the relation ofmcognition to its object, abysmal difficulties arise. / Cognition, the thing most taken for granted in natural thinking, suddenly emerges as a mystery. But I must be more exact. What is taken for granted in natural thinking is the possibility of cognition. Constantly busy producing results, advancing from discovery to discovery in newer and newer branches of science, natural thinking finds no occasion to raise the question of the possibility of cognition as such. To be sure, as with everything else in the world, cognition, too, will appear as a problem in a certain manner, becoming an object of natural investigation. Cognition is a fact in nature. It is the experience of a cognizing organic being. It is a psychological fact. As any psychological fact, it can be described according to its kinds and internal connections, and its genetic relations can be investigated. On the other hand cognition is essentially cognition of what objectively is; and it is cognition through the meaning which is intrinsic to it; by virtue of this meaning it is related to what objectively is. Natural thinking is also already active in this relating. It investigates in their formal generality the a priori connections of meanings and postulated meanings and the a priori principles which belong to objectivity as such; there comes into being a pure grammar and at higher stages a pure logic (a whole complex of disciplines owing