It is absurd to talk of one animal being higher than another...we consider those, where the intellectual faculties most developed as the highest. - A bee doubtless would [use] ... instincts as a criteria.

Ignorance more frequently begets confidence than does knowledge.

A novel according to my taste, does not come into the moderately good class unless it contains some person whom one can thoroughly love - and if a pretty woman, all the better.

Progress has been much more general than retrogression

Freedom of thought is best promoted by the gradual illumination of men’s minds which follows from the advance of science.

A surprising number [of novels] have been read aloud to me, and I like all if moderately good, and if they do not end unhappily-against which a law ought to be passed.

On seeing the marsupials in Australia for the first time and comparing them to placental mammals: “An unbeliever . . . might exclaim 'Surely two distinct Creators must have been at work'”