We ought never to be afraid to repeat an ancient truth, when we feel that we can make it more striking by a neater turn, or bring it alongside of another truth, which may make it clearer, and thereby accumulate evidence. It belongs to the inventive faculty to see clearly the relative state of things, and to be able to place them in connection; but the discoveries of ages gone by belong less to their first authors than to those who make them practically useful to the world