The most valuable thing in the Classical mathematic is its proposition that number is the essence of all things _perceptible to the senses_. Defining number as a measure, it contains the whole world-feeling of a soul passionately devoted to the “here” and the “now.” Measurement in this sense means the measurement of something near and corporeal. Consider the content of the Classical art-work, say the free-standing statue of a naked man; here every essential and important element of Being, its whole rhythm, is exhaustively rendered by surfaces, dimensions and the sensuous relations of the parts. The Pythagorean notion of the harmony of numbers, although it was probably deduced from music—a music, be it noted, that knew not polyphony or harmony, and formed its instruments to render single plump, almost fleshy, tones— seems to be the very mould for a sculpture that has this ideal. The worked stone is only a something in so far as it has considered limits and measured form; what it _is_ is what it _has become_ under the sculptor’s chisel. Apart from this it is a _chaos_, something not yet actualized, in fact for the time being a null. The same feeling transferred to the grander stage produces, as an opposite to the state of chaos, that of _cosmos_, which for the Classical soul implies a cleared-up situation of the external world, a harmonic order which includes each separate thing as a well-defined, comprehensible and present entity. The sum of such things constitutes neither more nor less than the whole world, and the interspaces between them, which for us are filled with the impressive symbol of the Universe of Space, are for them the nonent (τὸ μὴ ὅν). Extension means, for Classical mankind body, and for us space, and it is as a function of space that, to us, things “appear.” And, looking backward from this standpoint, we may perhaps see into the deepest concept of the Classical metaphysics, Anaximander’s ἄπειρον—a word that is quite untranslatable into any Western tongue. It is that which possesses no “number” in the Pythagorean sense of the word, no measurable dimensions or definable limits, and therefore no being; the measureless, the negation of form, the statue not yet carved out of the block; the ἀρχὴ optically boundless and formless, which only becomes a something (namely, the world) after being split up by the senses. It is the underlying form _a priori_ of Classical cognition, bodiliness as such, which is replaced exactly in the Kantian world-picture by that Space out of which Kant maintained that all things could be “thought forth.”