Philosophy is notorious for not answering the questions it tackles. Plato posed most of the central questions more than two millennia ago, and philosophers still haven't come to much consensus about them. Or at least, whenever philosophical questions begin to admit of answers, we start calling them scientific questions. (Astronomy, physics, chemistry, biology, and psychology all began as branches of philosophy.)

A common attitude on Less Wrong is "Too slow! Solve the problem and move on." The free will sequence argues that the free will problem has been solved.

I, for one, am bold enough to claim that some philosophical problems have been solved. Here they are:

  • Is there a God? No.
  • What's the solution to the mind-body problem? Materialism.
  • Do we have free will? We don't have contra-causal free will, but of course we have the ability to deliberate on alternatives and have this deliberation effect the outcome.
  • What is knowledge? (How do we overcome Gettier?) What is art? How do we demarcate science from non-science? If you're trying to find simple definitions that match our intuitions about the meaning of these terms in ever case, you're doing it wrong. These concepts were not invented by mathematicians for use in a formal system. They evolved in practical use among millions of humans over hundreds of years. Stipulate a coherent meaning and start using the term to successfully communicate with others.
There are other, smaller questions that I think are solved, too, but for now I'm curious: Which philosophical problems do you think are solved, and what is the answer?

New to LessWrong?

New Comment
44 comments, sorted by Click to highlight new comments since: Today at 8:40 PM

You use the words "solved" and settled" here, but I think they have very different meanings. In particular I can think of two relevant definitions of "settled": first, that someone, somewhere, has the correct answer; but second, that the correct answer is widely accepted, uncontroversial, and someone ignorant of the field can easily discover it just by reading a textbook..

I think your examples fall into the first category but not the second. According to the PhilPapers survey, only 32% of philosophers "accept" physicalism (a further 20% were "leaning towards" it). Another presentation of the poll said that 73% of philosophers either "lean toward or accept atheism".

When you can't get even three quarters of a field to even "lean toward" a position, I don't think you can call that a "settled question" under the second definition, especially compared to science where hopefully 100% of astronomers would either "lean toward or accept" heliocentrism. And when I complain that philosophers cannot settle questions, I am mostly referring to that second definition.

That PhilPapers survey is rather shocking to me. I knew about the "slow progress", but this is even more extreme than I thought.

Only 52% for physicalism? Majority support for moral realism? Complete indecision between deontology, virtue ethics and consequentialism? Almost complete indecision on the teletransporter problem? I despair...

Remember there is a great deal of specialisation in philosophy, so a political philosophers opinion on physicalism may not be accurate. Analogously, even a competent biologist would likely be wrong about the details of quantum mechanics.

This is not a surprise. Who wants to be a philosopher and who wants to be a scientist? Who likes to discuss the questions and who likes to discuss the answers? Who values consensus?

I think this objection, though I empathize with your bringing it up, is not really worth our time in considering.

Look, we all know, if we are honest, that there is a kind of skepticism (the result of realizing the problem of solipsism and following through on its logical consequences) that cannot be eliminated from the system. It is universal and infects everything.

For this reason, we really need to know more about why these folks have objections to these conclusions. Why we should give particular credence to the opinions of members of the philosophical professions is not obvious, as certainly this site testifies to the fact that you need not be a professor of philosophy to investigate philosophical questions. I suspect, but let us test, that in a fair number of cases the kind of doubts that are raised can be raised in any and every case of a claim of truth. If this is the case, then what matters it? I do not think our interests, practical as they seem largely to be, require that we be constantly limited by such doubts.

I am sure this reveals me as a scientist, but cannot we agree that in the cases of such doubt we should just move on and get on? We should, I think, care about doubts specific to the problems we are considering rather than doubts general to all problems, or we can be pretty sure that we are not going to get anywhere on any topic ever.

A pattern in philosophy is that once a problem is solved, it often seems obvious and trivial in retrospect. Never the less, here are some much-less-controversial solved problems (from

  1. Knowledge does not require certainty. But nor does justified true belief suffice.

  2. Psychological egoism is false: it is possible to act from non-selfish desires, i.e. for some good other than your own welfare.

  3. Rational egoism is false: we are not rationally required to always and only act in our own self-interest.

  4. (E.g. Moral) Principles may take situational variables into account without thereby sacrificing their claim to objectivity.

  5. The question whether God actually exists is independent of the question whether there is genuine normativity ("ought"-ness).

  6. Valuing tolerance needn't lead one to moral relativism. (Quite the opposite.)

  7. Red herrings may (and black ravens may not) constitute evidence that all ravens are black.

  8. It's not analytic (true by definition) that cats are animals. But it is metaphysically necessary: there is no possible world containing a cat that is not an animal.

Slightly more controversial:

  1. "Common-sense" morality, with its agent-relative ends, is self-defeating.

  2. Capitalism is not intrinsically just. (Libertarianism must be defended on consequentialist grounds, if any. Those who think otherwise are confused about the nature of property and coercion.)

  3. It is possible for desires (or ultimate ends) to be irrational. So there is more to rationality than just instrumental rationality.

  4. One may be harmed by events that took place prior to their coming into existence.

It's as though there were a separate subfield of mathematics devoted entirely to proposing axioms and definitions, and someone was defending that subfield against criticisms that it doesn't produce "results" simply by listing some of the definitions that have become standard.

Of course definitions are important, but this kind of exercise seems futile.

Number 8 is a case in point. It may as well simply state "Kripke's theory of alethic modal operators and natural kinds has become standard". Which is true, and Kripke's theory is interesting in many ways, but sometimes it's more of a hindrance than a help: There's this theory of "2 dimensional semantics" whose entire purpose (as far as I can tell) is to allow philosophers to pay lip service to Kripke's theory while ignoring it in practice.

(To fit the pieces together, follow the link above, substituting "cats" for "water" and "animals" for "H2O"; and also read Richard Chappell's post.)

Thanks for posting my list! Looking back, I think the third "more controversial" one (about the irrationality of some ultimate desires, e.g. Future Tuesday Indifference) probably doesn't belong on the list. I do think it is very interesting and probably true, but that's a different matter.

It's not analytic (true by definition) that cats are animals. But it is metaphysically necessary: there is no possible world containing a cat that is not an animal.

I disagree with this. First, to make sure I know what you mean, you're basically saying that "that cat-like thing I see" is not, by definition, a cat. If we took a full description of a cat's biology to be the definition then it would be an animal by definition. Did I get all that right?

I don't think it's possible to prove a statement to be synthetic (the opposite of analytic - do LessWrongians know these words?) unless you prove that there is no possible way to show something by definition. In this case, it seems that we have just failed to show that the statement was analytic rather than proving it to be synthetic.

I'm not sure I follow your objection. In natural language, the meaning of 'cat' is fixed by ostention, not descriptive stipulation. We (most of us, at least) mean something like "that cat-like thing I see". If it turns out that the cat-like creatures of our worlds are cleverly disguised robots, rather than animals, we would conclude that cats are robots, not that our world contains no cats. Hence the meaning of our word 'cat' does not include their animality.

You could, of course, introduce a new term 'shcat' which you stipulate means "cat-like animal". So then the situation I've described above would be one in which we learn that our world contains no shcats. But the English word 'cat' does not function like this. And the interesting Kripkean point is just that we can (and often do) define words by ostension, which can then display this interesting behaviour of featuring in claims that are metaphysically necessary but not analytic. That is: it's the possibility of such a distinction, rather than any particular instance of it, which is the really interesting thing here.

I agree with this. I do not know much about the philosophy of language, so I did not know that this was the consensus on the definitions of words like 'cat'.

I am not sure that there is a possible distinction in this case. It is metaphysically necessary that cats are necessary, but we have not proved it to be synthetic.

I would take such a list with care. The author claims that the only disagreements on such points come from grossly confused people, which he compares to creationists. Being a grad student at Princeton is a solid credential, but not enough that I would take him at face value while he advances as "settled" propositions that he needed to defend, and not simply present, on his blog.

(Disclosure: I find at least two of his defences of the statements above to be unconvincing, so I am pretty biased against him; at the same time, while I am certainly spottily educated on the subject, I still put enough weight on my own judgment and on the nature of my disagreements that I'm not going to adopt the assumption that I am the confused one.)

Fair enough. Out of interest, which ones did you disagree with?

Nr. 3 (he hinges it on an rather unconvincing argument that time displacement - i.e. caring for your future self - is comparable to agent displacement - i.e. caring for someone else) and Nr. 5 (the argument is fine, but he's arguing against what I consider a strawman - it's not that without God morality disappears from the hyperuranian realm, it's that it loses a universal judge-enforcer which has some pretty harsh implications, especially for a materialist).

I don't think it's a strawman. When you corner a theist on this point, she will often claim that god provides objective morality regardless of the existence of hell (or other punishments). They really are claiming that without God, morality disappears--hence the relativists can't justify anything schtick. And hence the standard non-answer to the Euthyphro dilemma, as opposed to simply admitting, "Yes, it's above him but he enforces it."



No, I did mean hyperuranian.

Oh. But aren't we more interested in whether there's morality in the hypouranian realm? Below the heavens, rather than above? I mean, imagine a theist (maybe it had better be a deist) who believes that God exists and determines moral values -- but only for other gods. If convinced that God doesn't exist after all, she might feel that morality had disappeared from the hyperuranian realm, but why would she care?

Hyperuranian realm = the world of ideas, as opposed to the world of physical matter. The proposition that blogger is attacking is that, without God, morality would lose its value as a concept. Quote:

it's daft to think that God's existence is necessary to ground normative ideals, because the whole point of ideals is that they float free from the mess of our actual reality.

Aha, gotcha. Thanks.

Mathematics is full of precise and illuminating solutions to previously-confusing philosophical problems; so much so that you might call mathematics itself "precise philosophy". For example:

  • What is the nature of space, extension, and continuity? Answer.

In general, whenever you see a "cryptic" definition of a concept in mathematics that generalizes but doesn't superficially resemble some previous concept, you're dealing with the answer to a question of the form "what is the 'philosophical essence' of concept X?"

Mathematicians have thus achieved the ultimate philosopher's dream: answers of the form "the meaning of life is 42" which are true and meaningful!

Zeno's paradoxes have been mentioned in another comment. For "theological" questions, see here.

Mathematicians have thus achieved the ultimate philosopher's dream

Plato agreed, which is why he held up geometry as the standard for judging other "sciences".

And much later, it was shown that the geometric "truths" that were settled questions do not describe the physical world as had been settled. Indeed, it turned out that there are many geometries other than Euclidean geometry. Solved problems need not stay solved, even in mathematics.

Number four is overreaching. If we had solved the "what is knowledge" problem, AI would already be a reality. The "answer" you give is at best a clearing away of one source of confusion.

I'd consider "the origin of life" a solved philosophical problem.

I'd consider "the origin of life" a solved philosophical problem.

I think one could say more generally that the first cause problem has been solved or almost solved, in the first sense that Yvain described. I am not a physicist, but from what I can tell, physicists are finding it less and less necessary to worry about the next step in an infinite regress.

Sorites / Ship of Theseus? Words, particularly those born of everyday usage rather than research papers, have boundaries that are fuzzy, until enough pioneers explore them and sharpen the map. You cannot say whether the ship is new because you never had to deal with this type of repairs before - Theseus' ship lies in the fuzzy boundary of "new". This is the time for you to re-draw the boundary with a sharper pen, either ahead of or behind Theseus' ship, and so establish an improved, more powerful definition of "new". i.e. Pretty much the same way you dismissed "what is art?".

I'm assuming you wouldn't consider problems that got solved by non-(directly)-philosophical means, such as Achilles and the tortoise (otherwise you could write a book just listing all the stuff that weirded out medieval philosophers). Would you consider problems that have not been solved so much as, shall we say, transcended, e.g. the liar's paradox?

One small aside I just realised: "philosophical problems" is a much less common turn of phrase than "philosophical questions". Could that be a (small) contributor to Western philosophy's notorious inertia? Having a "problem" would suggest that you are somehow worse off as long as it remains unsolved, whereas a "question" can also be an idle curiosity that you are free to tackle or ignore.

Taking "solved" to mean "there's only one right-thinking answer, given the arguments that have been raised", I would definitely agree with the questions you think are settled.

I'm also highly confident on:

  • Meta-ethics: moral realism or moral anti-realism? Anti-realism
  • Normative ethics: deontology, consequentialism, or virtue ethics? Consequentialism
  • Teletransporter (new matter): survival or death? Survival

I wrote up how I "derive" my ethical position here, where I'd hoped you'd see it, but the thread was a bit old by the time I posted.

My thoughts on the teleporter problem are not novel --- I agree with Robin Hansen's take here, although I'd put it a bit differently. I came to the answer when I described the problem to a friend and he told me immediately that I'd arrived at the reductio ad absurdem correctly but had failed to resolve it: the answer was that my definition of "myself" was broken, and that it's better to think there will just be a future-copy of me who thinks he was me, but I will not be him. This is true in general, as it is in the teleporter problem. If you're comfortable making life easy and pleasant for future-you, you can be just as comfortable making life easy and good for teleported-you.

So I think the teleporter is a very simple problem. It's just that the answer is hidden behind a strong adaptive intuition about what constitutes identity.

I seems to agree with your original list. I would phrase the free will one differently - both free will and determinism are useless concepts because we have no mechanism for contra-causality other than spirit-magic and we cannot predict our decisions even if they are causally produced.

Philosophy is notorious for not answering the questions it tackles.

I thought philosophy is about asking (right) questions, not (necessarily) answering them.

Philosophy might eventually retcon its self-image to that effect once most of its major problems have been solved by non-philosophers, but I'll view that about the same way I view certain crowds' insistence that religion has never been about making empirical claims.

Maybe in modern times a lot of academic philosophers are more interested in keeping questions open so they can keep writing papers on them, but I think most philosophers throughout history have at least sincerely wanted to know the answers to the questions they were thinking about.

I thought philosophy is about asking (right) questions, not answering them.

You were mistaken. :)

As you said: "Which philosophical problems do you think are solved, and what is the answer?"

I have proof of the existence of God, but I need a minimum of karma = 2 in order to publish in the discussion. Is there someone help me to have the opportunity to publish? Thank you.

I already had karma = 2, Thank you I already submitted on

Upvoted for novel audacity!

Hypothetically, you could upvote the rest of Seremonia's comments here if you want to see the article.


Thank you


Thank you




|Which philosophical problems do you think are solved, and what is the answer?

It's "There is God"

I think it is doubtful that any of the examples that you give have been solved/settled in any meaningful sense (particularly the last one).

If they were settled then those who disagree would have to be one of the following:

  • Unknowledgeable about the subject matter
  • Confused about the subject matter
  • Lying
  • irrational

However, there seem to be plenty of people who disagree with you who don't fall into the above categories.

From what you say it just sounds like you are saying that these are the issues that you are convinced about and which you cannot imagine being persuaded otherwise about. But on that kind of definition what is settled/solved will be person relative.

Are you able to give some kind of understanding to solved/settled where these issues come out as settled/solved and is also not person relative?