"It is impossible to divide the past into distinct, clearly defined periods and prove that one age ended and another began in a particular year, such as 476, or 1453, or 1789. Men do not and cannot change their habits and ways of doing things all at once, no matter what happens."

“In its amplest meaning history includes every trace and vestige of everything that man has done or thought since first he appeared on the earth. It may aspire to follow the fate of nations or it may depict the habits and emotions of the most obscure individual. Its sources of information extend from the rude flint hatchets of Chelles to this morning's newspaper. It is the vague and comprehensive science of past human affairs.”

“We are incredibly heedless in the formation of our beliefs, but find ourselves filled with an illicit passion for them when anyone proposes to rob us of their companionship. It is obviously not the ideas themselves that are dear to us, but our self-esteem, which is threatened.”

“It is a poor technic when attempting to convert one's neighbor to attack his beliefs directly, especially those of the sacred variety. We may flatter ourselves that we are undermining them by our potent reasoning only to find that we have shored them up so that they are firmer than ever. Often history will work where nothing else will. It very gently modifies one's attitude. Refutations are weak compared with its mild but potent operation. To become historically-minded is to be grown-up.”

“During the tenth and eleventh centuries the rule of the Church prohibiting the clergy from marrying appears to have been widely and publicly neglected in Italy, Germany, France, and England. To the stricter critics of the time this appeared a terrible degradation of the clergy, who, they felt, should be unencumbered by family cares and wholly devoted to the service of God. The question, too, had another side. It was obvious that the property of the Church would soon be dispersed if the clergy were allowed to marry, since they would wish to provide for their children. Just as the feudal tenures had become hereditary, so the church lands would become hereditary unless the clergy were forced to remain unmarried.”

“It is true that biologists have, many of them, given up what they call "Darwinism"; they have surrendered Spencer's notion of the hereditary transmission of acquired characters, and they even use the word "evolution" timidly and with many reservations. But this does not mean that they have any doubts that mankind is a species of animal, sprung in some mysterious and as yet unexplained manner from extinct wild creatures of the forests and plains.”