In my solitude I have pondered much on the incomprehensible subjects of space, eternity, life and death.

To the mass of mankind religion of some kind is a necessity

To say that mind is a product or function of protoplasm, or of its molecular changes, is to use words to which we can attach no clear conception

I think I have fairly heard and fairly weighed the evidence on both sides, and I remain an utter disbeliever in almost all that you consider the most sacred truths... I can see much to admire in all religions... But whether there be a God and whatever be His nature; whether we have an immortal soul or not, or whatever may be our state after death, I can have no fear of having to suffer for the study of nature and the search for truth.

Truth is born into this world only with pangs and tribulations, and every fresh truth is received unwillingly.

In all works on Natural History, we constantly find details of the marvellous adaptation of animals to their food, their habits, and the localities in which they are found.

There is a tendency in nature to the continued progression of certain classes of varieties further and further from the original type.