I'm not sure how to interpret the quotation marks in your first question; I'll assume they're inessential. Who decides what's true? No one, as far as I can see. One can recognize what's true, discover what's true, conclude that such-and-such is true, etc. But I don't think any of that amounts to deciding what's true. I'm not sure that even the president genuinely decides that it's true that so-and-so is pardoned; I think he decides to declare that so-and-so is pardoned, and his declaration then makes it true that so-and-so is pardoned. But he doesn't decide that his declaration makes it true. I'm not sure how to interpret the capitalization in your second question; I'll assume it's inessential. If you believe that Santa Claus exists, then as far as you're concerned Santa Claus exists. If that's what you mean by "true for me," then it's just another way of saying that you believe that Santa Claus exists, which of course doesn't make your belief true. If it did, then the concept of a false...

I strongly doubt that all definitions are human-made. Given the staggering number of stars that astronomers say exist, it seems highly likely that intelligent life has arisen in at least one other place -- intelligent life capable of creating languages and capable of creating explicit definitions for at least some of the items in those languages. All the definitions we currently know of are human-made, but the region of spacetime we've sampled is exceedingly small compared to what's out there.

Not as far as I can see. Indeed, I highly doubt that we've discovered all of the philosophical problems there are, and I'd be very surprised if the problems we have discovered all reduced in that way. What makes you suspect that they might? Consider, for example, the Paradox of the Heap: If we remove grains, one at a time, from a billion-grain heap of sand, when precisely does the heap cease to exist? The question has implications for much more serious matters than heaps of sand, and the answer is extremely controversial. I can't see how this paradox "reduce[s] to the metaphysical question of 'why?'." For starters, why what ?

In my experience anyway, defenders of the existence of objective moral truths don't typically rely on a James-style pragmatist theory of truth. Have a look at the SEP entry on "Moral Realism," available here . The author is someone who accepts the existence of objective moral truths (unless I'm very much mistaken!), and he doesn't mention James or pragmatism even once.

Your comment seems to be in tension with itself. You end it by suggesting that we adopt a version of relativism "that...would allow people to believe anything they want (without the need for justification)." Yet you begin your comment by apparently condemning, as "completely irrational," the beliefs of those who think pseudoscience or religion are irrational. I don't think you can have it both ways: relativism for their judgments, objectivism for your own. You ask, "Who defines what is rational?" I take it you have some definition in mind when you describe critics of pseudoscience and religion as "completely irrational." Relativism has an undeserved reputation for being open-minded. Those who think that they can "believe anything they want (without the need for justification)" should feel no pressure to keep their minds open to any evidence or arguments against what they believe.

You've asked a version of the very old philosophical question "Why be moral?" You may find something relevant to that question in the SEP entry linked here . I'd like to point out an assumption underlying your question. You seem to assume that someone has a rationale for acting morally only if acting morally serves his/her prudential self-interest (otherwise I can't see why you'd suggest that heaven is relevant to leading an ethical life). But why should we accept that assumption? Why must the answer to "Why be moral?" invoke something that's (arguably) nonmoral such as prudence? Why think that the ultimate or overriding rationale for doing something must be one's self-interest? In essence your question seems to be "Why does my doing the morally right thing always serve my long-term self-interest?" The answer, I'd say, is that there's no guarantee that it does . It might profit you in the long run to rob an innocent stranger if you'll never get caught; nevertheless, you...

Your question touches on a current debate within philosophy. You can find more about the debate by searching under "experimental philosophy" and "x-phi" on the web. Regardless of which side one takes, however, it's always important to know which kind of question (empirical, conceptual, logical, normative, or a mixture of those) one is trying to answer: the answer to "Which kind of question is that?" is a philosophical matter. In my experience, philosophers too often fail to recognize that the question they're asking has empirical aspects -- aspects that, as philosophers, they're not trained to investigate. If a question can be answered by polling or some other empirical method, then any philosopher who tries to answer it had better be properly trained in the relevant empirical method. Once the empirical results are in, the implications of those results are something that philosophers, as such, are well-equipped to work on.

You wrote: (i) "It seems that for classical logic to make sense of a contradiction in such a way that it leads to explosion...it must define what it means to hold a contradiction in a particular way" and (ii) "[W]ouldn't it be defined in some arbitrary way that forces us into the 'explosion' scenario?" Regarding (i): If the assertion "A is true and A is false" means anything, then surely it implies that A is true and implies that A is false. I can't think of another way to construe the assertion. Are you suggesting that a conjunction doesn't imply each of its conjuncts? Regarding (ii): How is it arbitrary to infer the truth of A and the falsity of A from the assertion "A is true and A is false"? Again, I can't think of another way to understand the assertion. As far as I know, paraconsistent logicians tend to object to inferring B from (A or B) and not-A: they point out that the inference relies on the implicit assumption that not-A rules out A, an assumption they reject.

Given premises P and not P, it is indeed valid to derive P. I don't know of any logical systems, including non-classical systems, that would deny the validity of that derivation. (A valid derivation needn't use all of its premises: "P; Q; therefore, P" is valid.) The derivation you gave isn't sound, however, because not all of the premises are true: it's guaranteed that one of the premises is false (even if we don't know which one). Yes, we're ascertaining the unsoundness of the derivation without knowing the content of its premises, but that's perfectly fine: If you know that the form of the derivation guarantees that it has a false premise, you don't need to know anything more in order to know that the derivation is unsound.

Your first question is an empirical question; we get a lot of those here. A sociologist or a legal historian might be able to answer it, but not a philosopher as such . But your second question seems less clearly empirical. If by "more irrefutable" you mean something like "supported by better arguments" or "less vulnerable to serious objections," then I'd say no based on what I know of religious and secular metaphysics. I'd recommend reading two recent articles: this one by Erik J. Wielenberg and this one by Wes Morriston . Both argue that a religious metaphysics of morality is less plausible than a secular metaphysics of morality and, furthermore, that the former metaphysics in fact depends on the latter. Note that position P can be less plausible than position Q even if P depends on (i.e., implies) Q.