“In human life, you will find players of religion until the knowledge and proficiency in religion will be cleansed from all superstitions, and will be purified and perfected by the enlightenment of real science.”

Letter to the Rev. George V. Coyne, S.J., Director of the Vatican Observatory, 1 June 1988
Source: [Russell, Robert J., Stoeger, William R., Pope John Paul II, Coyne, George V., 1990, John Paul II on science and religion: reflections on the new view from Rome, Vatican Observatory Publications]

Ten Years' Exile (Dix années d'exil, written 1810–1813, posthumously published 1821), ch. 16

The Varieties of Scientific Experience: A Personal View of the Search for God (2006)

Source: The Demon-Haunted World: Science as a Candle in the Dark

Source: Faith vs. Fact (2015), p. 258

Context: I make this chief distinction between religion and superstition, that the latter is founded on ignorance, the former on knowledge; this, I take it, is the reason why Christians are distinguished from the rest of the world, not by faith, nor by charity, nor by the other fruits of the Holy Spirit, but solely by their opinions, inasmuch as they defend their cause, like everyone else, by miracles, that is by ignorance, which is the source of all malice; thus they turn a faith, which may be true, into superstition.

Letter 21 (73) to Henry Oldenburg , November (1675)

Non-Progress: De Quincey's Toothache (p. 155)
Straw Dogs: Thoughts on Humans and Other Animals (2002)

Source: Why Evolution is True (2009), p. xvii