Next to being right in this world, the best of all things is to be clearly and definitely wrong, because you will come out somewhere. If you go buzzing about between right and wrong, vibrating and fluctuating, you come out nowhere; but if you are absolutely and thoroughly and persistently wrong, you must, some of these days, have the extreme good fortune of knocking your head against a fact, and that sets you all straight again.

Nothing can be more incorrect than the assumption one sometimes meets with, that physics has one method, chemistry another, and biology a third.

The more rapidly truth is spread among mankind the better it will be for them. Only let us be sure that it is the truth.

I cannot but think that he who finds a certain proportion of pain and evil inseparably woven up in the life of the very worms, will bear his own share with more courage and submission.

I am too much of a sceptic to deny the possibility of anything...

The man who is all morality and intellect, although he may be good and even great, is, after all, only half a man.

Extinguished theologians lie about the cradle of every science, as strangled snakes beside that of Hercules