cannot ultimately establish even the law of gravitation except by finding that it seems to explain all facts of the kind it applies to. But yet there is such a thing as natural science, and it has its degrees of necessity; and some things are pretty fully and generally established and shed great clearness wherever they apply, and some again are mere observations for which no reason or general probability whatever can be adduced.
Well, this is the sort of way, I suppose, in which we must conceive the problem of making representation instrumental to expression. I see the statue of the Discobolos, and I see that it represents a man in act to hurl a disc. Now to live myself into this representation, I must consider what a man is, and I must have some knowledge how his body works and balances, and so on. I cannot read off anything at all from the statue merely as a pattern in marble, as I could if it were a marble cube or sphere. This is the difficulty of representation as I stated it.
