Poets, and orators, and painters, and those who cultivate other branches of the liberal arts, have, without this critical knowledge, succeeded well in their several provinces, and will succeed: as among artificers there are many machines made and even invented without any exact knowledge of the principles they are governed by.

It is, I own, not uncommon to be wrong in theory, and right in practice: and we are happy that it is so.

Men often act right from their feelings, who afterwards reason but ill on them from principle; but as it is impossible to avoid an attempt at such reasoning, and equally impossible to prevent its having some influence on our practice, surely it is worth taking some pains to have it just, and founded on the basis of sure experience.

We might expect that the artists themselves would have been our surest guides; but the artists have been too much occupied in the practice: the philosophers have done little; and what they have done, was mostly with a view to their own schemes and systems; and as for those called critics, they have generally sought the rule of the arts in the wrong place; they sought it among poems, pictures, engravings, statues, and buildings.

But art can never give the rules that make an art.