It is a quantity having direction

Do I seem to say, "Let us eat and drink, for to-morrow we die?" Far from it; on the contrary, I say, "Let us take hands and help, for this day we are alive together."

We ought not to teach to little children, as a known fact, that which is not a known fact.

depends on the position of surrounding bodies, and may be described as the change of momentum of a body

It is a very serious thing to consider that not only the earth itself and all that beautiful face of Nature we see, but also the living things upon it, and all the consciousness of men, and the ideas of society, which have grown up upon …

If God holds all mankind guilty for the sin of Adam, if he has visited upon the innocent the punishment of the guilty, if he is to torture any single soul for ever, then it is wrong to worship him.

There is in the true man of science a desire stronger than the wish to have his beliefs upheld; namely, the desire to have them true.