In thinking about such matters, Music, as Schopenhauer shows, is wonderfully illustrative, because in creating music man recognises that he is creating a world of his own--apart from and not to be confused with that other world of Nature (in which he does not recognise any of his handiwork). Supposing a non-musical person were to examine and analyse the score of a Beethoven symphony, he would be in the same position as a man examining and analysing Nature by purely scientific or intellectual methods. He would discover the recurrence of certain groups among the notes, he would establish laws of their sequences, would make all kinds of curious generalisations about them, and point out some remarkable exceptions, would even very likely be able to predict a bar or two over the page; his treatise would be very learned, and from a certain point of view interesting also, but how far would he be from any real understanding of his subject? Let him change his method: let him train his ear, let him hear the symphony performed, over and over, till he understands its meaning and knows it by heart; and then he will know at any rate something of why each note is there, he will see its fitness and feel in himself the "law" of its occurrence, and possibly in some new case will be able to predict several bars over the page! The symphony is not understood by examination and comparison of the notes alone, but by _experience_ of their relation to deepest feelings; and Nature is not explained by laws, but by its becoming--or rather being felt to be--the body of Man; marvellous interpreter and symbol of his inward being. There is a kind of knowledge or consciousness in us--as of our bodily parts, or affections, or deep-seated mental beliefs--which forms the base of our more obvious and self-conscious thought. This systemic knowledge grows even while the brain sleeps. It is not by any means absolute or infallible, but it affords, at any moment in man's history, the axiomatic ground on which his thought-structures, scientific and other, are built. Thus the axioms of Euclid are part of our present systemic knowledge, and afford the ground of all our geometry structures. But as the systemic consciousness grows, the ground shifts and the structures reared upon it fall. All our modern science, for instance, is founded on the acceptation of mechanical cause and effect as a basic fact of consciousness; but when that base gives way the entire structure will cave in, and a new edifice will have to be reared. Similarly, when the human form becomes distinctly visible to us in the animals--as an unavoidable part of our consciousness--this consciousness will form a new base or axiom for all our thought on the subject, and the theory of evolution, as hitherto conceived by science, will be entirely transformed.