“Belief in God is apparently a psychological artifact of mammalian reproduction.”

We the People interview (1996)

Introduction, p. xix.
What Is This Thing Called Science? (Third Edition; 1999)

Source: He Still Moves Stones

Bombay, Second Public Talk (25 February 1962)
1960s
Context: The fact is there is nothing that you can trust; and that is a terrible fact, whether you like it or not. Psychologically, there is nothing in the world that you can put your faith, your trust, or your belief in. Neither your gods, nor your science can save you, can bring you psychological certainty; and you have to accept that you can trust in absolutely nothing. That is a scientific fact, as well as a psychological fact. Because, your leaders — religious and political — and your books — sacred and profane — have all failed, and you are still confused, in misery, in conflict. So, that is an absolute, undeniable fact.

Ibid., p. 375
The Book of Disquiet
Original: Em qualquer espírito, que não seja disforme, existe a crença em Deus. Em qualquer espírito, que não seja disforme, não existe crença em um Deus definido.

The Aquarian Conspiracy (1980), Chapter Thirteen, The Whole- Earth Conspiracy

"Do Animals Have Beliefs?" (1979); as quoted in The Case for Animal Rights by Tom Regan (University of California Press, 2004), p. 36 https://books.google.it/books?id=Y0tWjRmxFE4C&pg=PA36.

Source: Modularity of Mind (1983), p. 1

Source: Faith vs. Fact (2015), pp. 168-169