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

It has been generally the custom of writers on natural history to take the habits and instincts of animals as the fixed point, and to consider their structure and organization as specially adapted to be in accordance with them.

What birds can have their bills more peculiarly formed than the ibis, the spoonbill, and the heron?

I hold with Henry George, that at the back of every great social evil will be found a great political wrong

What we need are not prohibitory marriage laws, but a reformed society, an educated public opinion which will teach individual duty in these matters

There is, I conceive, no contradiction in believing that mind is at once the cause of matter and of the development of individualised human minds through the agency of matter

There might have been a hundred or a thousand life-bearing planets, had the course of evolution of the universe been a little different, or there might have been none at all. They would probably add, that, as life and man have been produced, that shows that their production was possible; and therefore, if not now then at some other time, if not here then in some other planet of some other sun, we should be sure to have come into existence; or if not precisely the same as we are, then something a little better or a little worse.