This art is music. It stands quite apart from all the others. In it we do not recognize the copy, the repetition, of any Idea of the inner nature of the world. Yet it is such a great and exceedingly fine art, its effect on man's innermost nature is so powerful, and it is so completely and profoundly understood by him in his innermost being as an entirely universal language, whose distinctness surpasses even that of the world of perception itself, that in it we certainly have to look for more than that exercitium arithmeticae occultum nescientis se numerare animi [exercise in arithmetic in which the mind does not know it is counting] which Leibniz took it to be.

Vol. I, Ch. III : The World As Representation: Second Aspect, as translated by Eric F. J. Payne (1958) - The World as Will and Representation (1819; 1844)