The Science Of Getting Rich, Wallace Wattles, 1910. Introduction, paragraph 2

It is expected that the reader will take the fundamental statements upon faith, just as he would take statements concerning a law of electrical action if they were promulgated by a Marconi or an Edison; and, taking the statements upon faith, that he will prove their truth by acting upon them without fear or hesitation.

Every man or woman who does this will certainly get rich; for the science herein applied is an exact science, and failure is impossible.

For the benefit, however, of those who wish to investigate philosophical theories and so secure a logical basis for faith, I will here cite certain authorities.