“Science is nothing but trained and organized common sense, differing from the latter only as a veteran may differ from a raw recruit: and its methods differ from those of common sense only as far as the guardsman's cut and thrust differ from the manner in which a savage wields his club.”

“Science is simply common sense at its best, that is, rigidly accurate in observation, and merciless to fallacy in logic.”

“The charm of history and its enigmatic lesson consist in the fact that, from age to age, nothing changes and yet everything is completely different.”

“The charm of history and its enigmatic lesson comsist in the fact that, from age to age, nothing changes and yet everything is completely different”

“[Responding to the Bishop of Oxford, Samuel Wilberforce's question whether he traced his descent from an ape on his mother's or his father's side]A man has no reason to be ashamed of having an ape for his grandfather. If there were an ancestor whom I should feel shame in recalling it would rather be a man—a man of restless and versatile intellect—who … plunges into scientific questions with which he has no real acquaintance, only to obscure them by an aimless rhetoric, and distract the attention of his hearers from the real point at issue by eloquent digressions and skilled appeals to religious prejudice.”

“If there is a country in the world where concord, according to common calculation, would be least expected, it is America. Made up as it is of people from different nations, accustomed to different forms and habits of government, speaking different languages, and more different in their modes of worship, it would appear that the union of such a people was impracticable; but by the simple operation of constructing government on the principles of society and the rights of man, every difficulty retires, and all the parts are brought into cordial unison. There the poor are not oppressed, the rich are not privileged. Industry is not mortified by the splendid extravagance of a court rioting at its expense. Their taxes are few, because their government is just: and as there is nothing to render them wretched, there is nothing to engender riots and tumults.”

“Extinguished theologians lie about the cradle of every science as the strangled snakes beside that of Hercules; and history records that whenever science and orthodoxy have been fairly opposed, the latter has been forced to retire from the lists, bleeding and crushed if not annihilated; scotched, if not slain.”