You might ask: "How long is this performance going to last?" And you might get the answer: "Two hours." You might also ask, more ambitiously, how long is this universe going to last?" And you might get the answer (from physicists presumably): "Forever." Now, those two answers seem similar; certainly they are grammatically similar responses to the two questions. And this might encourage you to think that "Forever" picks out a specific temporal duration, just as "two hours" does -- except that the first duration is a lot longer than the second. And then you might start to get a real headache trying to understand the nature of this duration "forever". But, that's not what "forever" means here. To say that the universe will last forever doesn't mean that there's some really big temporal interval, forever , during which it will be around; it means rather that there is no last temporal moment of the universe. So there is no really big temporal quantity of foreverness that you have to wrap...

(a) sounds a bit awkward and one might wonder whether it's ambiguous. Does it mean: (a1) You should make it be the case that (it is not the case that (you do not buy that book)), or (a2) It is not the case that (you should make it be the case that (you do not buy that book)). Using "S" to stand for "You should make it be the case that" and "N" for "It is not the case that", (a1) has the form: S(N(N( p ))). But (a2) has the form: N(S(N( p ))). (a2) does not mean the same as (b), which has the form: S( p ). But (a1) is arguably identical in meaning to (b). That's because "N(N( p ))" means the same as " p ". A cautionary note: In general, most people would agree that "N(N( p ))" means the same as " p ", that is, that a statement means the same as its double negation. What would a world look like, you might wonder, in which those statements differ in their truth or falsity? We can't even coherently describe it. I say "most people," though, because some have...

Thomas has given some examples of situations that are conceivable but not possible (in that they conflict with, say, laws of nature): for instance, in some sense one can imagine a puddle's turning into a human being, though such a transformation flies in the face of what we believe is physically possible. But there are also circumstances which are physically possible of which we can form no picture. For instance, it's physically possible for there to be a chunk of quartz with a thousand facets, though I cannot imagine such a thing. The question presupposes that we use the terms "conceivable" and "possible" in just one way, which is doubtful. For a little more, see Question 71 .

For an answer to a similar question, see Question 773 .

And it might be worth adding that the absence of a "method" doesn't really distinguish philosophy from any other interesting rational inquiry. There is no "mathematical method". And, contrary to how many people speak, there is no "scientific method" either, at least not in any interesting sense of "method".

You might also look at the response to Question 27 .

It's true that logic doesn't tell us how to do certain things, like dance or play badminton. Philosophers often distinguish between knowing how to do something and knowing that something is the case. The latter kind of knowledge is often termed propositional knowledge , because what we know is that a particular proposition holds. For instance, our knowledge that London is in England is an instance of propositional knowledge; the proposition we know is proposition that London is in England . Now let's return to the question of how to justify logical inferences. Can we hope to do so by pointing to any abilities (knowings-how) that we possess (abilities which, I grant you, are not given to us simply in virtue of our appreciating logical entailment relations)? I don't think so. Abilities, knowings-how, aren't really routes to knowledge. (They might be prerequisites for our acquisition of knowledge—for instance, if I don't have the ability to walk to the window, I might not be able...

Most of Thomas' response focuses on your observation that once one's dead one's "not conscious", and he nicely tries to clear a space for the possibility of harm's being done to someone even if that person doesn't feel the harm. But in most of the cases he considers, there is still someone to be the subject of the misfortune: the clueless entrepreneur, for instance, is still around to have his interests set back (even if he's not aware that that is happening). Death is rather peculiar, however, in that it's a misfortune that eliminates from the world the subject of the misfortune. (Of course, someone's death might be a misfortune for others. But as you note, we put people to death to punish the very people who, if the punishment is carried out, are no longer around.) Once one's dead, not only does one cease to experience things but one ceases to have interests too. That's what makes your question hard. It's really the question the Ancients (and everyone else) argued about: whether one's own death...

Many kinds of considerations convince people. Everyone, not just philosophers, naturally sorts those considerations into "good" reasons and "bad" ones. People might sometimes disagree on where to draw the line, but most everyone agrees there's a line to be drawn. The good reasons are considerations that are relevant to the truth of the claim in question; the bad ones, irrelevant. Relevant in this sense: the truth of the considerations demands, or at least makes more likely, the truth of the claim being argued for. Turns out that we've made a lot of progress in understanding this relation of relevance. Logic studies one corner of it: that which concerns entailment relations between claims, that is, when the truth of one proposition forces the truth of another. With this knowledge in hand, we can see that people are often convinced by arguments that do not provide good reasons for their conclusion. And also, that they sometimes fail to be convinced by good arguments. Arguments that...

I think many would disagree with you. Unless you're an amazing genius, most likely "your philosophy" won't be terribly interesting in comparison to the pinnacles that have been reached over the millenia. It's true that everyone has philosophical questions. (Just browse this site!) And a good introduction to philosophy should help students see how many of the questions they've been asking throughout their lives are very philosophical ones and how they connect to the ones that inspired the great figures in the tradition. But while many might also have answers to these questions, these are likely not as sophisticated, interesting, and beautiful as some of the answers developed by the greats. Of course, students should be encouraged to take a critical stance toward those answers, to subject them to intense scrutiny. It's more likely in that way that students will develop a deep and interesting philosophy of their own.