- The theist and the scientist are rival interpreters of nature, the one retreats as the other advances.
- The Existence of God (1913), p. 84.
- A law of nature is not a formula drawn up by a legislator, but a mere summary of the observed facts — a "bundle of facts." Things do not act in a particular way because there is a law, but we state the "law" because they act in that way.
- The Existence of God (1913).
- The sentiments attributed to Christ are in the Old Testament. They were familiar in the Jewish schools and to all the Pharisees, long before the time of Christ, as they were familiar in all the civilizations of the earth — Egyptian, Babylonian, and Persian, Greek, and Hindu.
- The Sources of the Morality of the Gospels (1914).
- Evolution throws a wonderful light on all the struggles, eccentricities, tortuous developments of the human conscience in the past. It is the only theory of morals that does. And evolution throws just as much light on the ethical and social struggle today; and it is the only theory that does. What a strange age ours is from the religious point of view! What a hopeless age from the philosopher's point of view! Yet it is a very good age, the best that ever was. No evolutionist is a pessimist.
- The Human Origin of Morals (1926), p. 59.
- I once met a pompous ass of a believer who had this religious-sense theory in an exaggerated degree. It is not at all my custom to obtrude the question of religion in conversation, but somebody maliciously tried to draw the man into debate about God with me. He would say nothing but, with comic solemnity: "I know there is a God." He would not explain further, but his meaning was clear. He felt it. He sensed it. And there is but one possible form in which he could have given precise expression to his actual experience. He was visibly annoyed, but still silent, when I put it. It is: "I have a strong conviction that God exists."
- The Psychology of Religion (1927), p. 42.
- If a single one of these gentlemen is correct, if a believer of any type is right, the essential truth for man, the real drama of life, in comparison with which the secular story of the race, is a puppet-show and the unfolding of the universe is a triviality, is the dialogue of the immortal soul and the eternal God. Yet it seems that there is nothing in the world so hard to discover as this. The theory refutes itself.
- The Psychology of Religion (1927), p. 47.
- An idea or institution may arise for one reason and be maintained for quite a different reason.
- The Psychology of Religion (1927), p. 48.
- Today we know not only that there is a terrible amount of disorder in the heavens — great catastrophes or conflagrations occur frequently — but evolution gives us a perfectly natural explanation of such order as there is. No distinguished astronomer now traces "the finger of God" in the heavens; and astronomers ought to know best.
- The Story of Religious Controversy (1929), p. 86.
- Any body of men who believe in hell will persecute whenever they have the power.
- What Gods Cost Man (1933).
- The absence of theistic belief...
- Defining the word "atheism", in A Rationalist Encyclopedia (1950).
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