We have seen that the senses and intuitions, the various emotions and faculties, such as love, memory, attention and curiosity, imitation, reason, etc., of which man boasts, may be found in an incipient, or even sometimes in a well-developed condition, in the lower animals.

It strikes me that all our knowledge about the structure of our Earth is very much like what an old hen would know of the hundred-acre field in a corner of which she is scratching.

Music was known and understood before words were spoken.

We may confidently come to the conclusion, that the forces which slowly and by little starts uplift continents, and that those which at successive periods pour forth volcanic matter from open orifices, are identical.

It is mere rubbish thinking, at present, of origin of life; one might as well think of origin of matter.

We are not here concerned with hopes or fears, only with truth as far as our reason permits us to discover it.

Whenever I have found that I have blundered, or that my work has been imperfected, and when I have been contemptuously criticised, and even when I have been overpraised, so that I have felt mortified, it has been my greatest comfort to say hundreds of times to myself that 'I have worked as hard as I could, and no man can do more than this.'