Reason, observation, and experience; the holy trinity of science.

The history of the world shows that when a mean thing was done, man did it; when a good thing was done, man did it.

I believe that labor is a blessing. It never was and never will be a curse. It is a blessed thing to labor for . . . the ones you love. It is a blessed thing to have an object in life - something to do - something to call into play your best thoughts, to develop your faculties and to make you a man.

If the account given in Genesis is really true, ought we not, after all, to thank this serpent? He was the first schoolmaster, the first advocate of learning, the first enemy of ignorance, the first to whisper in human ears the sacred word liberty, the creator of ambition, the author of modesty, of inquiry, of doubt, of investigation, of progress and of civilization.

Shakespeare was an intellectual ocean, whose waves touched all the shores of thought; within which were all the tides and waves of destiny and will; over which swept all the storms of fate, ambition and revenge; upon which fell the gloom and darkness of despair and death and all the sunlight of content and love, and within which was the inverted sky lit with the eternal stars -- an intellectual ocean -- toward which all rivers ran, and from which now the isles and continents of thought receive their dew and rain.

I would rather that we all should go to eternal chaos, to black and starless night, than that just one soul should suffer eternal agony.

My heart was filled with gratitude, with thankfulness, and went out in love to all the heroes, the thinkers who gave their lives for the liberty of hand and brain... to all the wise, the good, the brave of every land, whose thoughts and deeds have given freedom to the sons of men. And then I vowed to grasp the torch that they had held, and hold it high, that light might conquer darkness still.