Page:An Essay on the Principle of Population (1798).djvu/258

 distinction that I see, between a philosophical conjecture, and the assertions of the Prophet Mr. Brothers, is, that one is founded upon indications arising from the train of our present observations, and the other has no foundation at all. I expect that great discoveries are yet to take place in all the branches of human science, particularly in physics; but the moment we leave past experience as the foundation of our conjectures concerning the future; and still more, if our conjectures absolutely contradict past experience, we are thrown upon a wide field of uncertainty, and any one supposition is then just as good as another. If a person were to tell me that men would ultimately have eyes and hands behind them as well as before them, I should admit the usefulness of the addition, but should give as a reason for my disbelief of it, that I