In regard to the amount of difference between the races, we must make some allowance for our nice powers of discrimination gained by a long habit of observing ourselves.

Every new body of discovery is mathematical in form, because there is no other guidance we can have.

Natural selection acts solely by accumulating slight successive favorable variations, it can produce no great or sudden modification; it can act only by very short steps.

The survival or preservation of certain favoured words in the struggle for existence is natural selection.

The main conclusion here arrived at ... is that man is descended from some less highly organized form.

We will now discuss in a little more detail the Struggle for Existence.

The instruction at Edinburgh was altogether by lectures, and these were intolerably dull, with the exception of those on chemistry.