He must reflect on what he himself is doing.

He must compare his work with the original, and try to discover how far he has succeeded, and where he has gone astray.

The more faithfully he tries to reproduce what he has seen, the clearer and surer will be his insight into the less palpable properties of things,--into those details, those aspects, those qualities, which do not reveal themselves to the first careless glance, but which will gradually reveal themselves to those who will take the trouble to discover them.

When he is asked to reproduce things which are intrinsically beautiful--flowers, branches, buds, shells, butterflies, and the like--he begins to realise that if his work is to be successful, he must do justice to many impalpable, though not imperceptible, details which go to the making up of beauty.

So the sense of beauty, the feeling for it, the desire to bring it into his work, grows up in his heart; and a new kind of fidelity--fidelity to _feeling_ rather than to _fact_ (if I may speak for the moment in the delusive language of dualism)--begins to weave itself into his artistic consciousness.
If there is any school in England in which fidelity to feeling has evolved itself out of fidelity to fact, that school is in the village of Utopia.