When you ask why people believe in logic, it seems to me that the commonest answer is, "It works." But that answer seems problematic to me; how do you know it won't stop working? I guess what I'm asking is -- are logical laws nothing more than empirical regularities, models of how things behave? Are logical laws any different from empirical laws? Is there any stronger reason to have faith in logic apart from the fact that it works and has always worked?

Yes: As I see it, logical laws are different from empirical regularities. Many of our empirical predictions come true, but some of them don't, and in any case it's not hard to imagine any particular empirical prediction turning out false. I predict that the chair I'm now sitting in won't levitate before I finish answering your question, but it's easy for me to imagine being wrong in that prediction. Indeed, I can even imagine that universal gravitation stops working in the way we've become used to. But what would it be to suppose that the laws of logic stop working? Would it be to suppose that the laws of logic stop working and continue to work exactly as they always have? If yes, why? If no, why not? (Presumably not because the laws of logic would prevent it!) So I'm not sure it's possible to entertain the supposition that the laws of logic stop working. Indeed, I'm not sure that there's any such supposition in the first place. In my view, the question "What makes us so confident that it will never...

I don't know if this a philosophical question or scientific question, So this is my question, If A create all things, is it logically safe to say that A is uncreated?

The analogy to printing money fails. There's an obvious difference between (a) "I create everything except myself" and (b) "I print all the money except what's in my wallet." Given the impossibility of creating my own creator, (a) implies that I am uncreated. By contrast, (b) doesn't imply that the money in my wallet is unprinted. Maybe Professor Westphal assumes that it's possible for someone to create his/her own creator. Maybe he imagines a time-travel loop in which, say, X creates Y in 1900 and then Y goes back in time to create X in 1800. I think such a scenario is conceptually incoherent, because I think that "X creates Y in 1900" implies "Y doesn't exist prior to 1900." But I suppose others might interpret "creates" differently.

Professor Westphal wrote: "If I create everything except myself, then of course it follows that I do not create myself. But...does it follow that I am uncreated? I can't see how it does. For one thing, there could be someone else who created me...." If I am created, then I have one or more creators, each distinct from me. If I am created and I create everything except myself, then I must create my own creator(s), which is no more coherent than self-creation. Hence I must be uncreated. See my original reply. Professor Westphal's interpretation of John 1:3 makes the verse at least possibly true, but at the cost of making it oddly redundant: "All made things were made by God; and no made things were made without God." The second clause comes so close to simply restating the first clause that it could hardly count as "evidence" in favor of the first.

It's a philosophical question. No scientist, as such, will have any particular expertise for answering it. If A created all things, then it follows that A created itself , since presumably only a thing (rather than literally nothing) can do any creating. But the notion that A created itself seems to me to be logically inconsistent: in order for A to do any creating, A must exist, and in order for A to be created (i.e., to be brought into existence) A can't yet exist. So I conclude that it's impossible for A to create all things. However, if A created everything else , i.e., everything distinct from A, then I think it does follow that A is uncreated. Otherwise, A would have to create A's own creator(s), which seems to me to be logically impossible. I myself think it's impossible for anything to create everything else, because I think that there are abstract objects (such as numbers, or the laws of logic) that exist necessarily and that are necessarily uncreated. So those things, at least,...

Why do we need a contrast to recognize a sensation? For example -; Think of hearing the same sound since your birth and think that you are hearing it without any variations. We will fail to recognize that we are perceiving a sensation and we won't be able to recognize the sense organ. Iam only 15,Forgive me if my question is fallacious. Thanks.

Thanks for your interesting question. I don't think there's anything fallacious about it. But I do think that, at bottom, it's an empirical question -- one that we can't expect to answer just by thinking hard about it. What you say in answer to it seems plausible to me: If all that I ever receive at my auditory organs is a totally undifferentiated sound, no matter what I do, then it's hard to see what function my auditory organs are performing for me or why I would even be aware that I had them. But I think that a confident answer to your question depends on properly gathered empirical data. You might look into the psychology literature to see if anyone has investigated this topic.

If God is the creator of the universe and all the living and non living things , Can he create or recreate himself ?

Because I think it's self-contradictory to say that God could literally create or re-create himself, I think believers in a Creator God must say this: God created all of the created things in the universe, but those things exclude God himself (and also Platonic abstract objects such as the laws of logic). For a bit more detail about why, you might look at my answer to Question 25260 .

In my amateur philosophy club, my friend told me that modal ontological argument is false because its premise, It's possible that a perfect being exists, doesn't make sense. He argued that it is logically equivalent to say "it is possible that it is necessary", which means 'there exists at least one possible world in which all possible worlds have this objects in them.' So, according to his analysis, that premise make possible worlds in a possible world, which is absurd and makes a danger of infinite regress. But I think he misunderstood the argument. I think what actually that premise says is "there is at least one possible world that has a object which is in every possible world." I think this is implied when the argument says that "if something possibly necessarily exists, then it necessarily exists." Am I wrong?

Excellent question. It's great to hear that you belong to a philosophy club. As I see it, if the modal-ontological argument fails, it's not because the locution "It is possible that it is necessary" is absurd or ill-formed or meaningless. The opening premise of the modal-ontological argument can be expressed without using the possible worlds idiom: There could have been a necessarily existing God (where "could have been" is construed as consistent with "is"). The idea is that even atheists are supposed to concede that a necessarily existing God is at least logically possible: logically speaking, there could have been such a thing (even if, according to atheists, there isn't). Granted the possibility of a necessarily existing God, the argument then uses the modal principle "If it's possible that it's necessary that G, then G," letting "G" in this case stand for the proposition that God exists. Conclusion: God actually exists. In my view, the argument can be challenged for assuming (1) the above...

Some people define some things (which they truly may be or are) Impossible. 'Impossible' has a humane meaning in itself. But... If 'something' is really impossible... then why can you think that? If something is impossible... then why did the neurons in your brain have that thought? It must've been impossible for them to think of something which is not possible.

I'll assume, just for simplicity, that by a "thought" you mean a belief and by "something impossible" you mean a proposition that cannot possibly be true . I hope my assumptions aren't off the mark. (I'm not a neuroscientist, so I'll say nothing about how neurons work.) If my assumptions are correct, then your question becomes "How can anyone believe a proposition that cannot possibly be true?" One answer is this: "Easy! For example, many people down through the ages believed that they had accomplished the famous geometric construction known as squaring the circle . But the proposition they believed cannot possibly be true, because squaring the circle is impossible, as was finally proven in 1882. Those who believed the proposition obviously didn't see the impossibility of the construction." An opposing answer is this: "They can't! Indeed, we can understand the behavior of those misguided geometers only if we attribute to them a false belief that could have been true, such as the belief that a...

If humans are just a bunch of extremely complicated gears working together, how can we have self-awareness?

Short answer: Because some bunches of extremely complicated gears are capable of self-awareness. Longer answer: We need to ask whether the reductive term "just" in your question makes the question tendentious (i.e., biased). To the question "If humans are just like the non-self-aware bunches of gears that we understand best -- such as the bunch of gears in a clock -- then how can they be self-aware?" the answer is clearly "They can't." But the latter question isn't interesting, so presumably it's not the question you intended to ask. To put it another way, humans can be bunches of gears (using "gears" only metaphorically) without being merely bunches of gears. It could well be that when a bunch of gears gets complicated enough, it becomes capable of self-awareness. Exactly how that happens is a question for neuroscience rather than for philosophy.

I suppose it is very difficult do define "truth" in an informative way (without just giving a synonym or something like that). Can you explain why it is so? Or is it easy?

One reason that it's difficult to define "truth" might be that the word stands for a concept that's too basic, too fundamental, to be informatively defined in terms of other concepts. I myself think that truth is a property of some propositions and therefore, derivatively, a property of some sentences. Which propositions? The true ones! Which sentences? The ones that express true propositions! The proposal that we can't say more than that is sometimes known as "deflationism" about truth. For much more, see this SEP entry .

Is there really a strong distinction between understanding what a proposition means and believing or disbelieving it? It strikes me that if I believe a proposition while my opponent does not, one way to explain the disagreement is to say that he misunderstands either that proposition or some related proposition. And so if we really did both understand all of the propositions in question, we'd have to agree about them as well.

I'd say that in many cases there's indeed a difference between grasping a proposition and believing the proposition, i.e., believing it to be true. To take a well-known example from mathematics, Georg Cantor believed that the Continuum Hypothesis is true, whereas Kurt Gödel believed it's false. Both were brilliant mathematicians; I see no reason to think that their disagreement arose from either man's misunderstanding the proposition in question or some related proposition. But not all cases are like that. Consider the proposition that all bachelors are unmarried. Anyone who fails to believe that proposition, I'd say, fails to grasp it, because grasping the proposition implies believing the proposition. At any rate, I can't make sense of the idea that someone could grasp that proposition without believing it.

Does an universal affirmative (A) premise entail a particular affirmative (I) one? I mean "All men are mortal" entails "Some men are mortal" or not? This is somehow confusing. Since, if you think that in a relation with set theory, it is impossible for (I) not to be entailed by (A). (A) intuitively entails (I). However, when looking at the opposition of square and applying, for example, tree method to prove the entailment, it results that (A) does not entail (I).

In Aristotle's syllogistic logic (including in his square of opposition), "All men are mortal" implies "Some men are mortal." But in the standard logic of the past 100 or so years, that implication doesn't hold. This failure of implication arises because modern standard logic construes "All men are mortal" as a universal quantification over a conditional statement: "For anything at all, if it's a man then it's mortal." Intuitively, I think we can see why the universally quantified statement can be true even if no men exist. Compare "For anything at all, if it's a unicorn then it's a unicorn," which seems clearly true despite the fact that (let's assume) no unicorns exist. In modern standard logic, then, "All men are mortal," "No men are mortal, " and "All men are immortal" come out true if in fact no men exist. Importantly, "Some men are immortal" does not come out true in those circumstances. A similar lesson applies in set theory, in which "All of the members of the empty set are even" and...

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