Remember that [scientific thought] is the guide of action; that the truth which it arrives at is not that which we can ideally contemplate without error, but that which we may act upon without fear; and you cannot fail to see that scientific thought is not an accompaniment or condition of human progress, but human progress itself.
A human being always acts and feels and performs in accordance with what he imagines to be true about himself and his environment...For imagination sets the goal ‘picture’ which our automatic mechanism works on. We act, or fail to act, not because of ‘will,’ as is so commonly believed, but because of imagination.