No slavery can be abolished without a double emancipation, and the master will benefit by freedom more than the freed-man.

Life is like walking along a crowded street--there always seem to be fewer obstacles to getting along on the opposite pavement--and yet, if one crosses over, matters are rarely mended.

We live in the hope and faith that, by the advance of molecular physics, we shall by-and-by be able to see our way as clearly from the constituents of water to the properties of water, as we are now able to deduce the operations of a watch from the form of its parts and the manner in which they are put together.

When I reached intellectual maturity and began to ask myself whether I was an atheist, a theist, or a pantheist; a materialist, or an idealist; a Christian, or a freethinker; I found that the more I learned and reflected, the less ready was the answer; until, at last, I came to the conclusion that I had neither art nor part with any of these denominations, except the last.

Give unqualified assent to no propositions but those the truth of which is so clear and distinct that they cannot be doubted. The enunciation of this first great commandment of science consecrated doubt.

A drop of water is as powerful as a thunder-bolt.

The known is finite, the unknown infinite; intellectually we stand on an islet in the midst of an illimitable ocean of inexplicability. Our business in every generation is to reclaim a little more land, to add something to the extent and the solidity of our possessions.