Space being the generalised concept of extended form, and time that of motion without reference to any contents, it is naturally impossible to think the non-existence of space and time. Thinking is an act, it is a process; and any act, any process, any event, is a reality which implies or presupposes the existence of the forms of reality. We can think of matter without reference to form, i. e. we can have the abstract idea of matter; but we cannot think that there is any matter void of form. This does by no means prove that form has nothing to do with matter. On the contrary, it proves that form and matter are inseparable. The form of existence need not therefore be called “the basis” of existence, it is simply one universal feature of existence. And the form of existence being bound up with existence itself, it is necessary that any thinking existence in so far as it is real, in so far as it is at the same time an object and part of the objective world should also be in possession of the conditions to evolve the idea of form out of itself through inner experience. This inner experience of experimenting with pure forms is also a kind of experience. It is not a purely subjective process; it is a subjective process to the thinking subject, which to other subjects, however, would appear as an objective process. The laws of pure form as stated in the sciences of purely formal thought, are not merely subjective; they possess objective validity. It is true and from our standpoint a matter of course that the laws of form are _a priori_, which means, they hold good for any pure form. Modern positivism, such as we defend it, is monistic. We consider the entire world as one great whole and do not forget that all noumenal representations of certain features of the world, of matter, mind, form, even of things and our own souls included, are mere abstractions. Reality itself remains undivided and indivisible. Abstract concepts are mental symbols invented to represent certain features of reality. But although we can in our mind separate these features and distinguish them from other features, in the world of reality they cannot be cut out or thought of as things in themselves. Granting the oneness of reality which dawns upon us instinctively before consciousness is fully matured, we are inevitably led to the conception that there is but one form of reality, which implies that there is but one space and one time. III. FORM NOT IMPORTED BY THE MIND INTO REALITY.