“Every argument for God and every attribute ascribed to Him rests on a false metaphysical premise. None can survive for a moment on a correct metaphysics....Existence exists, and only existence exists. Existence is a primary: it is uncreated, indestructible, eternal. So if you are to postulate something beyond existence—some supernatural realm—you must do it by openly denying reason, dispensing with definitions, proofs, arguments, and saying flatly, “To Hell with argument, I have faith.” That, of course, is a willful rejection of reason.Objectivism advocates reason as man’s sole means of knowledge, and therefore, for the reasons I have already given, it is atheist. It denies any supernatural dimension presented as a contradiction of nature, of existence. This applies not only to God, but also to every variant of the supernatural ever advocated or to be advocated. In other words, we accept reality, and that’s all.”

“The argument goes something like this: "I refuse to prove that I exist," says God, "for proof denies faith, and without faith I am nothing.”

“He who denies the existence of God, has some reason for wishing that God did not exist.”

“Reason excludes faith," Alessandro responded, watching the blood-red mite as it made a dash for the rim. "It's deliberately limited. It won't function with the materials of religion. You can come close to proving the existence of God by reason, but you can't do it absolutely. That's because you can't do anything absolutely by reason. That's because reason depends on postulates. Postulates defy proof and yet they are essential to reason. God is a postulate. I don't think God is interested in the verification of His existence, and, therefore, neither am I. Anyway, I have professional reasons to believe. Nature and art pivot faithfully around God. Even dogs know that.”

“Now it is such a bizarrely improbable coincidence that anything so mind-bogglingly useful could have evolved purely by chance that some thinkers have chosen to see it as the final and clinching proof of the non-existence of God.The argument goes something like this: "I refuse to prove that I exist,'" says God, "for proof denies faith, and without faith I am nothing.""But," says Man, "The Babel fish is a dead giveaway, isn't it? It could not have evolved by chance. It proves you exist, and so therefore, by your own arguments, you don't. QED.""Oh dear," says God, "I hadn't thought of that," and promptly vanishes in a puff of logic."Oh, that was easy," says Man, and for an encore goes on to prove that black is white and gets himself killed on the next zebra crossing.”

“[There is] a widespread approach to ideas which Objectivism repudiates altogether: agnosticism. I mean this term in a sense which applies to the question of God, but to many other issues also, such as extra-sensory perception or the claim that the stars influence man’s destiny. In regard to all such claims, the agnostic is the type who says, “I can’t prove these claims are true, but you can’t prove they are false, so the only proper conclusion is: I don’t know; no one knows; no one can know one way or the other.”The agnostic viewpoint poses as fair, impartial, and balanced. See how many fallacies you can find in it. Here are a few obvious ones: First, the agnostic allows the arbitrary into the realm of human cognition. He treats arbitrary claims as ideas proper to consider, discuss, evaluate—and then he regretfully says, “I don’t know,” instead of dismissing the arbitrary out of hand. Second, the onus-of-proof issue: the agnostic demands proof of a negative in a context where there is no evidence for the positive. “It’s up to you,” he says, “to prove that the fourth moon of Jupiter did not cause your sex life and that it was not a result of your previous incarnation as the Pharaoh of Egypt.” Third, the agnostic says, “Maybe these things will one day be proved.” In other words, he asserts possibilities or hypotheses with no jot of evidential basis.The agnostic miscalculates. He thinks he is avoiding any position that will antagonize anybody. In fact, he is taking a position which is much more irrational than that of a man who takes a definite but mistaken stand on a given issue, because the agnostic treats arbitrary claims as meriting cognitive consideration and epistemological respect. He treats the arbitrary as on a par with the rational and evidentially supported. So he is the ultimate epistemological egalitarian: he equates the groundless and the proved. As such, he is an epistemological destroyer. The agnostic thinks that he is not taking any stand at all and therefore that he is safe, secure, invulnerable to attack. The fact is that his view is one of the falsest—and most cowardly—stands there can be.”

“One particularly poor argument in defence of eating meat is that if humans did not eat animals, those animals would not have been brought into existence in the first place. Humans would simply not have bred them in the numbers they do breed them. The claim is that although these animals are killed, this cost to them is outweighed by the benefit to them of having been brought into existence. This is an appalling argument for many reasons. First, the lives of many of these animals are so bad that even if one rejected my argument one would still have to think that they were harmed by being brought into existence. Secondly, those who advance this argument fail to see that it could apply as readily to human babies that are produced only to be eaten. Here we see quite clearly that being brought into existence only to be killed for food is no benefit. It is only because killing animals is thought to be acceptable that the argument is thought to have any force.”