"Nothing is easier than to admit in words the truth of the universal struggle for life, or more difficult—at least I have found it so—than constantly to bear this conclusion in mind."

"The mystery of the beginning of all things is insoluble by us; and I for one must be content to remain an agnostic."

"Ultimately, the universe must be the outcome of chance."

"I had no intention of writing an autobiography, but I found myself doing so."

"To kill an error is as good a service as to establish a new truth."