I'm never encouraged when readers cannot read and understand simple declarative sentences in the English language. But after blogging for more than 30 months and discussing religion and philosophy on the internet for a decade, I'm rarely surprised. Much as I dislike repeating myself, I will do so. Even if it were true (which it's not) that "Atheists... don't give an account of how they can know" about causation an induction, it is necessary to acknowledge that we do not have such an account before we can begin to create one. Organizing wildly contradictory religious "models" — models that give no account of knowledge more sophisticated than an invisible sky-fairy magically putting ideas into our heads — in some systematic way and leaving the resolution of those contradictions to some vague debate on unspecified grounds just avoids beginning that search for truth. Even if atheism were to bring nothing at all to the philosophical table, it would be rational and sensible to reject religious thought and admit profound ignorance. If after millennia they are unable to give us anything at all better than magical sky-fairies and consensus by the sword, then we are rationally entitled to explicitly acknowledge we are starting from nothing at all.We are certain some element or elements of a theory — a set of statements about the world — are false if the theory entails false statements about observation.There cannot be any "true" statement about reality once one rejects the concept that truth can transcends the empirical world. You are correct that there are as many models of truth and reality as there are religions--more, even. This is a debate for the respective adherents to those models. But to reject any truth that is not empirically observable is to cut oneself off at the knees. At the very least, atheists must posit that objects in the world have causal relationships with one another, that the future will resemble the past, and so on. Religion is simply an organized, systematic way to organize these transcendental truths.
Atheists certainly don't reject causation and induction, but they don't give an account for how they can know it. They simply refuse to acknowledge the transcendental truths they rely upon. This is disingenuous.
But of course there is something. There were atheists before scientific naturalism, but it is no surprise that atheism has flourished under scientific naturalism, which does not just recognize the failures and vacuity of what passes for "epistemology" in religion but gives us a powerful way of explaining features of the world both gross and subtle in a more sophisticated way than invoking magic.
Even an inattentive reader should note the glaring contradiction in Kowal's comment: in almost the same breath he complains that atheists "don't give an account" of knowledge while also undermining the account we do give, i.e. empiricism. Just this discrepancy alone forces the reader to choose which of two uncomfortable interpretations is the most charitable: either Kowal is insane, he is simply too stupid to detect this rather obvious contradiction, or he is intentionally trying to deceive his readers. If he does not like the epistemic account that scientific naturalism does in fact give, let him say so: to critique an account he does not acknowledge the existence of too greatly shocks the mind of those unpracticed in religious doublethink and cognitive dissonance.
Worse yet, Kowal must reach decades back to the beginning of the 20th century (or perhaps to the middle of the 18th) to find a natural epistemology he can criticize with cognitive abilities deficient in competence or honesty.
It is simply false that modern scientific naturalism — the sort of naturalism practiced for centuries by actual scientists and explicitly described by at least some philosophers of science for decades — "reject[s] any truth that is not empirically observable." Even the most misguided of the logical positivists and naive empiricists would not have gone so far: even they admitted truths derived from an empirical foundation, even if those derived truths were themselves not empirically observable.
But of course problems with the naive empiricism of the 20th century were anticipated in the 18th by David Hume (objections that Kowal mentions without crediting Hume, an atheist). We cannot directly observe either causality or consistency over time, and much to the dismay of the naive empiricists, we cannot rigorously deduce these features of the world from the directly observable evidence. (There are a lot of other problems with logical positivism and naive empiricism, not the least of which is that the systems themselves are neither observable nor deducible from observation.)
Philosophers are little better than theologians, and it is unsurprising that anyone who reads only philosophy might think that this naive view constitutes the core of scientific thought. There are intelligent philosophers who have propounded more sophisticated concepts, but their work is buried in a mound of bullshit exceeded in scope and elaboration only by theology. The atheist criticism that finding the diamonds of theological sensibility is simply too difficult to be worth the trouble applies equally to philosophy*. Kowal's misunderstanding of scientific naturalism is excusable and correctable in a way that his "bad food and not enough of it" contradiction about the very existence of a natural epistemology is not.
*I have for various reasons decided to go to college in my old age. Despite my interest, I've rejected philosophy as a subject of academic study: the bullshit to sense ratio is too high for me to have any hope of making a meaningful contribution to anything but the edifice of bullshit itself. There is too little bullshit in science for a person to make a substantial contribution on the basis of only clarity and honesty: science demands competence, competence I lack both the time and alas! natural talent to develop. Economics and political science seem just about right: enough bullshit that an honest man of mediocre competence can make a contribution; enough sense (I hope) that the contribution can be meaningful.
Modern scientific naturalism shares two features of theology. First, both systems make guesses about how the world might be. We do not directly know the world is causal, and we cannot (as we have discovered) deduce the world is causal from what we do directly know. In order to talk about causality, we have to introduce the concept without knowledge or even any real confidence as whether it's actually true. Second, despite their protestations of universal truth, scientific naturalism and theology are dynamic: one way or another, when these systems fail to correspond to the world of experience, both actually change.
But — and this is a very substantial but indeed — from these similarities scientific naturalism departs radically from religious faith. In religious faith, our core guesses about God (and thus God's world) are upheld "come what may". Our articles of faith are utterly immune from change (until an authority changes them). Anything and everything else might change — we might even deny experience itself (who are you going to believe?
Under scientific naturalism, however, none of our guesses are immune from criticism. Everything is, at least formally, subject to change. Similarly, no authority can declare any guess as immune from change; no one requires the permission of any authority to change any part of any theory.
More importantly, a theory that predicts more (in a specific sense) is, under scientific naturalism, considered worse than a theory that predicts less. A theory that predicts that we will see an object move is worse than a theory that predicts that we will see an object move in a particular direction at a particular velocity. The first theory predicts more: our theory is consistent with observation if we see the object move up or down, left or right, fast or slow; the second theory predicts less: movement in one direction only and at one velocity only.
In contrast, it is no fault under theology if our core faith predicts more or less. God's love is equally compatible with slavery or abolition; His hatred of homosexuality equally compatible with loving gay marriage as with discord; His contempt of women equally compatible with women's demonstrable competence as with their failure; His divine creation equally compatible with life-friendly physical law as with constant miraculous intervention; His intention to create a race of beings to worship and adore Him equally compatible with a 6,000 year-old universe with the Earth at its center as with a universe of such cosmic scale and scope that all of human history is no more significant than the mold in my shower is to all of terrestrial civilization.
Our scientific naturalistic theories about the world are true because they explain and predict this world; they are valuable because they predict only this world. Theology is compatible with any old world we might find ourselves in: change the laws of physics, remove them altogether, transform billions of light years of galaxies, clusters and superclusters to a uniform distribution of a hundred stars or even lanterns in a quintessential firmament, chop scores of elements from the periodic table and rearrange them with a throw of the dice, and not one word of the vast edifice of theological bullshit created over the last ten thousand years would have to change.
Kowal admits that theology and religion lack any epistemic system. In his own words, all we can do is organize and systematize all the contradictory models and theories about the world: we can do nothing to choose between these theories other than a handwaving mention of some vague debate (a "debate" that throughout history has all too often been conducted through the media of murder, rape, slavery, torture, conquest, oppression and genocide). Indeed scientific naturalism has developed a way to choose between these models and — while Kowal complains in that we have no way to choose — he complains in the same breath that our epistemic system is fatally flawed because it does choose, and it chooses against the arrant superstitions and vacuous bullshit of theology.
When Glendower famously boasted, "I can call spirits from the vasty deep," Hotspur astutely retorted, "Why, so can I, or so can any man; But will they come when you do call for them?" Answers are easy: I can answer any question, or so can any man; but are they true? Theologians can indeed answer any question, but we suffer not from a lack of answers but from a surfeit. We know that scientific materialism can not just answer some questions, but we can know that those answers and only those answers are true. If, by applying some distinction we are left with some questions entirely unanswered, with every candidate so far rejection, that is but a small price to pay for knowing that other answers really are true. Answers are easy: we can always think up more answers and test them out.
It would of course be disingenuous or at least incomplete to extol the virtues of scientific naturalism without mentioning legitimate philosophical objections.
Science is, of course, a human endeavor, and its pursuit susceptible to the ordinary intellectual and moral vices typical of human beings. Our scientific knowledge is dependent on what we choose to study, the kinds of knowledge we choose to pursue, and our answers are dependent on the questions we choose to ask. Science is no universal panacea, a machine we can put questions into and be confident of always or even often get true answers. The best we can say about science is that sometimes it makes some distinctions. But just sometimes is incomparably better than never, and that sometimes is on the basis of ordinary logical thought and the evidence of our senses, not the pronouncements of ridiculous men in silly hats or the elimination of dissent by the sword and the prison cell.
Strictly speaking, scientific naturalism does not separate theories into true and false, it separates theories into definitely false, not definitely false and bullshit: "When you have eliminated the impossible, whatever remains, however improbable, must be the truth." We cannot know the theory of universal gravitation with the certainty we know that "there are infinitely many prime numbers" is a theorem of the axioms of arithmetic. If for this reason you don't want to label scientific naturalism as knowledge, so much worse for your view of knowledge. When you can demonstrate the truth of General Relativity or Quantum Mechanics with deductive certainty, let me know. Until then, I'll happily trade certainty of nothing for confidence in not just something but quite a lot while you play solipsistic games you could pursue without distraction if you put out your eyes and stopped up your ears.
We cannot apply scientific naturalism to scientific naturalism without circularity. But scientific naturalism as a method is not itself a theory about the world; it is simply a language game we play, a game we play not because we can somehow prove it itself is "true" but because we find it useful, a utility that — because we are uninterested in the what appears to be its the sole utility for justifying abominable behavior — that religion has never and apparently cannot provide.
Indeed it is the theologians whom we must accuse of intellectual procrastination. They have, to be sure, been diligent about providing answers, but after ten thousand years we are still waiting for them to give us a way — any way, however imperfect, that appeals not to our prejudice but our reason — to separate the the meaningful answers from the bullshit and the true answers from the false.