Heraclitus has as his royal property the highest power of intuitive conception, whereas towards the other mode of conception which is consummated by ideas and logical combinations, that is towards reason, he shows himself cool, apathetic, even hostile, and he seems to derive a pleasure when he is able to contradict reason by means of a truth gained intuitively, and this he does in such propositions as: "Everything has always its opposite within itself," so fearlessly that Aristotle before the tribunal of Reason accuses him of the highest crime, of having sinned against the law of opposition. Intuitive representation however embraces two things: firstly, the present, motley, changing world, pressing on us in all experiences, secondly, the conditions by means of which alone any experience of this world becomes possible: time and space. For these are able to be intuitively apprehended, purely in themselves and independent of any experience; _i.e.,_ they can be perceived, although they are without definite contents. If now Heraclitus considered time in this fashion, dissociated from all experiences, he had in it the most instructive monogram of all that which falls within the realm of intuitive conception. Just as he conceived of time, so also for instance did Schopenhauer, who repeatedly says of it: that in it every instant exists only in so far as it has annihilated the preceding one, its father, in order to be itself effaced equally quickly; that past and future are as unreal as any dream; that the present is only the dimensionless and unstable boundary between the two; that however, like time, so space, and again like the latter, so also everything that is simultaneously in space and time, has only a relative existence, only through and for the sake of a something else, of the same kind as itself, _i.e.,_ existing only under the same limitations. This truth is in the highest degree self-evident, accessible to everyone, and just for that very reason, abstractly and rationally, it is only attained with great difficulty. Whoever has this truth before his eyes must however also proceed at once to the next Heraclitean consequence and say that the whole essence of actuality is in fact activity, and that for actuality there is no other kind of existence and reality, as Schopenhauer has likewise expounded ("The World As Will And Idea," Vol. I., Bk. I, sec. 4): "Only as active does it fill space and time: its action upon the immediate object determines the perception in which alone it exists: the effect of the action of any material object upon any other, is known only in so far as the latter acts upon the immediate object in a different way from that in which it acted before; it consists in this alone. Cause and effect thus constitute the whole nature of matter; its true being _is_ its action. The totality of everything material is therefore very appropriately called in German _Wirklichkeit_ (actuality)--a word which is far more expressive than