Page:An Essay on the Principle of Population (1798).djvu/373

 sufficient yet remains to be done for mankind, to animate us to the most unremitted exertion. But if we proceed without a thorough knowledge, and accurate comprehension of the nature, extent, and magnitude, of the difficulties we have to encounter, or if we unwisely direct our efforts towards an object, in which we cannot hope for success; we shall not only exhaust our strength in fruitless exertions, and remain at as great a distance as ever from the summit of our wishes; but we shall be perpetually crushed by the recoil of this rock of Sisyphus.