Perhaps I may be allowed to repeat here that my purpose in preparing this book was to strengthen not only science but religion. I have never had any tendency to scoffing, nor have I liked scoffers. Many of my closest associations and dearest friendships have been, and still are, with clergymen. Clergymen are generally, in our cities and villages, among the best and most intelligent men that one finds, and, as a rule, with thoughtful and tolerant old lawyers and doctors, the people best worth knowing. My aim in writing was not only to aid in freeing science from trammels which for centuries had been vexatious and cruel, but also to strengthen religious teachers by enabling them to see some of the evils in the past which, for the sake of religion itself, they ought to guard against in the future.
Quoted in his Autobiography, vol. 2.