If the hypothesis of evolution is true, living matter must have arisen from non-living matter; for by the hypothesis the condition of the globe was at one time such, that living matter could not have existed in it, life being entirely incompatible with the gaseous state.

The saying that a little knowledge is a dangerous thing is, to my mind, a very dangerous adage. If knowledge is real and genuine, I do not believe that it is other than a very valuable possession, however infinitesimal its quantity may be. Indeed, if a little knowledge is dangerous, where is the man who has so much as to be out of danger?

The great end of life is not knowledge but action.

Perhaps the most valuable result of all education is the ability to make yourself do the thing you have to do, when it ought to be done, whether you like it or not; it is the first lesson that ought to be learned; and, however early a man's training begins, it is probably the last lesson that he learns thoroughly.

I cannot say that I am in the slightest degree impressed by your bigness, or your material resources, as such. Size is not grandeur, and territory does not make a nation. The great issue, about which hangs true sublimity, and the terror of overhanging fate, is what are you going to do with all these things?

The man of science who commits himself to even one statement which turns out to be devoid of good foundation loses somewhat of his reputation among his fellows, and if he be guilty of the same error often he loses not only his intellectual, but his moral standing among them. For it is justly felt that errors of this kind have their root rather in the moral than in the intellectual nature.

The students of physical science are not unfrequently told that their pursuits unfit them for the estimation of moral probability. And it may be so, for I am afraid that to those who are accustomed to severe reasoning, either in the province of Science or in that of Law, reasoning from 'moral probability' is apt to be regarded as a process of accumulating inconclusive arguments, in the hope that a great heap of them may, at least, look as firm as one good demonstration.

All truth, in the long run, is only common sense clarified.

I really have no claim to rank myself among fatalistic, materialistic, or atheistic philosophers. Not among fatalists, for I take the conception of necessity to have a logical, and not a physical foundation; not among materialists, for I am utterly incapable of conceiving the existence of matter if there is no mind in which to picture that existence; not among atheists, for the problem of the ultimate cause of existence is one which seems to me to be hopelessly out of reach of my poor powers. Of all the senseless babble I have ever had occasion to read, the demonstrations of these philosophers who undertake to tell us all about the nature of God would be the worst, if they were not surpassed by the still greater absurdities of the philosophers who try to prove that there is no God.

Logical consequences are the scarecrows of fools and the beacons of wise men.