“Each religion makes scores of purportedly factual assertions about everything from the creation of the universe to the afterlife. But on what grounds can believers presume to know that these assertions are true? The reasons they give are various, but the ultimate justification for most religious people’s beliefs is a simple one: we believe what we believe because our holy scriptures say so. But how, then, do we know that our holy scriptures are factually accurate? Because the scriptures themselves say so. Theologians specialize in weaving elaborate webs of verbiage to avoid saying anything quite so bluntly, but this gem of circular reasoning really is the epistemological bottom line on which all 'faith' is grounded. In the words of Pope John Paul II: 'By the authority of his absolute transcendence, God who makes himself known is also the source of the credibility of what he reveals.' It goes without saying that this begs the question of whether the texts at issue really were authored or inspired by God, and on what grounds one knows this. 'Faith' is not in fact a rejection of reason, but simply a lazy acceptance of bad reasons. 'Faith' is the pseudo-justification that some people trot out when they want to make claims without the necessary evidence.But of course we never apply these lax standards of evidence to the claims made in the other fellow’s holy scriptures: when it comes to religions other than one’s own, religious people are as rational as everyone else. Only our own religion, whatever it may be, seems to merit some special dispensation from the general standards of evidence.And here, it seems to me, is the crux of the conflict between religion and science. Not the religious rejection of specific scientific theories (be it heliocentrism in the 17th century or evolutionary biology today); over time most religions do find some way to make peace with well-established science. Rather, the scientific worldview and the religious worldview come into conflict over a far more fundamental question: namely, what constitutes evidence.Science relies on publicly reproducible sense experience (that is, experiments and observations) combined with rational reflection on those empirical observations. Religious people acknowledge the validity of that method, but then claim to be in the possession of additional methods for obtaining reliable knowledge of factual matters — methods that go beyond the mere assessment of empirical evidence — such as intuition, revelation, or the reliance on sacred texts. But the trouble is this: What good reason do we have to believe that such methods work, in the sense of steering us systematically (even if not invariably) towards true beliefs rather than towards false ones? At least in the domains where we have been able to test these methods — astronomy, geology and history, for instance — they have not proven terribly reliable. Why should we expect them to work any better when we apply them to problems that are even more difficult, such as the fundamental nature of the universe?Last but not least, these non-empirical methods suffer from an insuperable logical problem: What should we do when different people’s intuitions or revelations conflict? How can we know which of the many purportedly sacred texts — whose assertions frequently contradict one another — are in fact sacred?”

“There are a whole lot of religious people in America, including the majority of Democrats. When we abandon the field of religious discourse—when we ignore the debate about what it means to be a good Christian or Muslim or Jew; when we discuss religion only in the negative sense of where or how it should not be practiced, rather than in the positive sense of what it tells us about our obligations toward one another; when we shy away from religious venues and religious broadcasts because we assume that we will be unwelcome—others will fill the vacuum. And those who do are likely to be those with the most insular views of faith, or who cynically use religion to justify partisan ends.”

“There are two ways of persuading men of the truths of our religion; one by the power of reason, the other by the authority of the speaker.We do not use the latter but the former. We do not say: 'You must believe that because Scripture, which says it, is divine,' but we say that it must be believed for such and such a reason. But these are feeble arguments, because reason can be bent in any direction.”

“...a man is not in any difficulty in making a reply according to his faith ... to those who try to defame our Holy Scripture. ... when they produce from any of their books a theory contrary to Scripture ... either we shall have some ability to demonstrate that it is absolutely false, or at least we ourselves will hold it so without any shadow of a doubt. ...let us choose [the doctrine] which appears as certainly the meaning intended by the author. ... For it is one thing to fail to recognize the primary meaning of the writer, and another to depart from the norms of religious belief.”

“We can move to legalize same-gender civil marriage without harming any religious institution or dictating any change to the beliefs and practices of any faith. Religious opposition to civil marriage for same-gender couples irrelevant to the civil, public debate. You're opposed to gay marriage on religious grounds? Fine! Don't authorize your clergy to act as an agent of the State in any such unions. But don't deprive the rest of, who believe that such rites are good and holy, of our constitutional rights to practice our own freedom of religion. We don't live in a theocracy where some one understanding of religion and faith dictates what the State will and will not do. This religious argument against the right to marry for gay and lesbian couples is simply bogus. And unconstitutional. Religious belief should have no bearing whatsoever on the legal right to marry.”

“You frequently state, and in your letter you imply, that I have developed a completely one-sided outlook and look at everything in terms of science. Obviously my method of thought and reasoning is influenced by a scientific training – if that were not so my scientific training will have been a waste and a failure. But you look at science (or at least talk of it) as some sort of demoralizing invention of man, something apart from real life, and which must be cautiously guarded and kept separate from everyday existence. But science and everyday life cannot and should not be separated. Science, for me, gives a partial explanation of life. In so far as it goes, it is based on fact, experience and experiment. Your theories are those which you and many other people find easiest and pleasantest to believe, but so far as I can see, they have no foundation other than they leaf to a pleasanter view of life (and an exaggerated idea of our own importance)...I agree that faith is essential to success in life (success of any sort) but I do not accept your definition of faith, i.e. belief in life after death. In my view, all that is necessary for faith is the belief that by doing our best we shall come nearer to success and that success in our aims (the improvement of the lot of mankind, present and future) is worth attaining. Anyone able to believe in all that religion implies obviously must have such faith, but I maintain that faith in this world is perfectly possible without faith in another world…It has just occurred to me that you may raise the question of the creator. A creator of what? ... I see no reason to believe that a creator of protoplasm or primeval matter, if such there be, has any reason to be interested in our significant race in a tiny corner of the universe, and still less in us, as still more significant individuals. Again, I see no reason why the belief that we are insignificant or fortuitous should lessen our faith – as I have defined it.”