Institutio Oratoria

Had Praxiteles attempted to carve a statue out of a millstone, I should have preferred a rough block of Parian marble to any such statue. On the other hand, if the same artist had produced a finished statue from such a block of Parian marble, its artistic value would owe more to his skill than to the material. To conclude, nature is the raw material for education: the one forms, the other is formed. Without material art can do nothing, material without art does possess a certain value, while the perfection of art is better than the best material.

More important is the question whether rhetoric is to be regarded as one of the indifferent arts, which in themselves deserve neither praise nor blame, but are useful or the reverse according to the character of the artist; or whether it should, as not a few even among philosophers hold, be considered as a virtue.