Not only the mental, but also the physical advance of mankind is essentially dependent upon the discovery of new truths. Men's physical actions are determined not alone by their inherited and acquired tendencies and the influence of external nature upon them, but also by their ideas; as a man thinks, so also to a large extent does he act. Nations who do not adopt new ideas do not either mentally or physically advance, but change only so far as their immediate surroundings change; the Chinese are a remarkable example of this; even the tendencies which men inherit, were largely produced in their ancestors by the influence of ideas. The great fact of the essential dependence of human progress upon new knowledge, is a truth, the importance of which to man cannot be over-estimated, and is one which statesmen, ministers of religion, and philanthropists should seriously study.
Much of the apparent advance of this nation however is not real. The great bulk of our newly published knowledge, even that which is scientific, and considered by the public to be new, consists, not of new truths, but of old ones dressed in new forms of expression:--
"The tale repeated o'er and o'er, With change of place and change of name. Disguised, transformed, and yet the same We've heard a hundred times before."--_Longfellow._
It falls to the lot of but comparatively few men to discover or evolve important new truths. The great majority of learned men also, have through all historic time been occupied, and are still, not in evolving new ideas, but in re-expressing old ones in different forms of words; the literary spirit, is in civilised nations, almost universal. In ordinary writings it is a rare circumstance to meet with an important and really new idea; it is usually in books written by men who are acquainted or imbued with the great principles and truths of science, that the newest demonstrable ideas are most frequently found. The difference between evolving new ideas, and re-expressing and permutating old ones; largely characterises the dissimilarity of the scientific and the literary and theological minds. All however are necessary to the welfare of mankind, the former to advance and the other to maintain the condition of man. If all were not necessary they would probably not exist.