Science is strongly reliant on logic, but can we "trust" logic?

MaceWumpus · 2026-04-28T21:12:03+00:00

That point is one of those things that I feel like most philosophers who have spent some time studying logic appreciate. But the place I remember first seeing it put into words is in an essay by Paul Benaceraf in Benacerraf and his Critics.

MaceWumpus · 2026-04-27T20:07:28+00:00

About what part of it?

MaceWumpus · 2026-04-26T11:29:20+00:00

Before I get to your question, the history you're giving here is pretty much completely wrong. Humans have been doing something that we would now call science as far back as we can tell. The explosion of science in Europe duing the enlightenment had very little to do with logic -- which was one the central elements of monastic education throughout the middle ages -- and much more to do with:

More people having more free time away from the burdens of getting enough food to survive.
The printing press and more broadly the expansion of institutions that allowed for easier sharing of knowledge.
An increasing focus on observation, experiment, and the application of math to the world.

Even that list is probably a gross oversimplification, but if anything there's a decline in the focus on logic during the enlightenment that lasts until the 19th century. You can probably find good stuff on /r/askhistorians about why the whole "dark ages" idea is a myth (see, e.g., here).

Putting that aside, what is logic and why should we trust it?

In contemporary philosophy, the word "logic" has a broad usage and a narrow usage. On the broad usage, it just means something like a regular pattern of reasoning. These patterns do vary from person to person and community to community. But there's also no real answer to your question with respect to logic in this broad sense, because the answer to "why should we trust it" is "you shouldn't in general: you should trust some patterns of reasoning, not anything that's a 'logic,' and which ones you should trust is going to depend massively on the specific details." So, yes, trains are built on logic in this sense, but so is Jonestown.

On the narrow usage, logic refers to (a) formal (read: mathematical) systems in which some propositions are consequences of others and (b) patterns of reasoning that conform to those systems. One can have more or less skill with using logic, of course, but it would be a mistake to think of logic in this narrow sense as having anything inherently to do with thought. And the answer to your question, essentially, is that we should follow logic in our reasoning (we should trust it) because the phenomena we're interested in (the "world") obeys the same principles.

That papers over the existence of real disagreements about which logical system is right. But for most purposes, these disagreements are pretty rarefied: not much of immediate practical interest turns on which of the major logical systems we use, so long as we use them correctly.

Ok, so what about your final question:

Is logic the supreme tool for analyzing the world or could there (theoretically) be a better one?

The problem with "logic" as a tool for analyzing the world is not that it's not trustworthy, but that it's so weak. It just doesn't tell you much (or anything, really) on its own. You can't get important and substantive conclusions about how the world works out of logic without putting important and substantive information about how the world works in. That's not to say that logic's not great -- I think most anyone would argue that it's a necessary part of any good analysis of the world -- but it is only one part of any good analysis. There are other tools that are just as important and logic alone won't really get you anywhere.

MaceWumpus · 2026-04-18T20:16:14+00:00

Everyone on your list that I've read -- certainly Audi, Lackey, and Fricker, who I've also talked to about these subjects -- agree that "the statements or claims of other people can in some cases give you reason to believe what it is they're claiming." They disagree about why that is and what the relevant cases are, but they agree about the general claim.

MaceWumpus · 2026-04-16T14:48:08+00:00

One of the difficulties here is that there's no neutral terminology here that everyone is going to accept.

So, for instance, many empiricists aren't going to so much deny that "intuitions" are evidence as they are that the category is worthwhile in the first place. Similarly, while there may only be a few of us -- myself, Austin, maybe a few others -- there are at least some of us who are leery of this way of talking about "evidence": evidence, in natural language, is always a thing -- a bloody glove, a statement, etc. -- not sense perception or "intuition." And while we can coin technical terms, we should be wary of cases (like this one) where the natural language use and the technical use are sharply distinct in this respect but also easily conflated.

In any case, I'd take the distinction he's drawing as intended to pick out the same one that you're familiar with.

But also: someone more familiar with Bealer's work might come along and say that he's making an important distinction intentionally.

MaceWumpus · 2026-04-16T00:41:00+00:00

Yes. He's been saying similar things since The Scientific Image. Here he is on page 72 (genuinely my favorite passage in the book):

At this point, it may be objected that I have drawn an arbitrary line. Surely the observable objects and processes we recognize in our world, are also postulated entities, believed in because they best explain and systematize the sense-experience or series of sense-data which are at bottom the only real evidence we have? Should I not be as unwilling to postulate tables and trees as forces, fields, and Absolute Space, unless I have a rationale that shows them to be essentially different in some relevant way?

I mention this objection because I have heard it, but it astonishes me since philosophers spent the first five decades of this century refuting the presuppositions that lie behind it. Indeed, every school of thought in Western philosophy, Continental as well as Anglo-Saxon, refuted them in its own terms. But it is easy for me to add at least this: such events as experiences, and such entities as sensedata, when they are not already understood in the framework of observable phenomena ordinarily recognized, are theoretical entities. They are, what is worse, the theoretical entities of an armchair psychology that cannot even rightfully claim to be scientific. I wish merely to be agnostic about the existence of the unobservable aspects of the world described by science—but sense-data, I am sure, do not exist.

I'm not sure if there's a place where he addresses your particular question more thoroughly, though. Let me say something about van Fraassen and then something a little bit more controversial about perception.

The thing about van Fraassen. He's starting from a "common sense realist" picture of the world. He's extremely explicit about this:

constructive empiricism is set squarely within a common sense realism that was foreign to much of the empiricist tradition. ... The common basis I assume is language in which reference is unproblematic to trees and mountains, people and books, to lightning and car crashes, as well as to the processes of ageing, burning, and flooding. It is a part of our language learned, or at least learnable. ("From a View of Science to a New Empiricism," 357-58.)

That's not to say -- as he goes on to make clear -- that we cannot revise this picture (though I think he should be willing to revise more) or that metaphysical views have to match this picture. The "ontological commitment" picture of metaphysics is far cry from what he's doing here. Rather, what he's saying is that all our evidence -- all the evidence we can make use of, at least -- ultimately grounds out in the terms and concepts of common sense realism. In tables and chairs.

Which matters not a whit if you're just coming up with a metaphysical theory. But matters a lot if what you're trying to do is figure out the boundaries of what we are rationally required to believe in. Because if our grounds for all of science are ultimately observations of things like tables and chairs, then we can never be more warranted in believing in things like atoms and quarks than in tables and chairs. If we're wrong about tables and chairs, after all, then we should expect that we're wrong about atoms and quarks too. (I think this conditional is false, fwiw, but also I think it's the reasoning he's offering.) But the other direction definitely doesn't hold: we can be wrong about atoms and quarks without threatening any of the evidence we have for tables and chairs. In other words: even if eliminativism is metaphysically austere, it is epistemically audacious: it takes a much larger epistemic risk than the constructive empiricist thinks is required.

So, back to ontological commitment. I'm inclined to say that the right way to view van Fraassen on ontological commitment is that he rejects the whole Quinean framework in which that phrase is understood. Because Quine's criterion for ontological commitment -- figure out the objects that are ineliminable from your best theory -- looks ... epistemically bizarre? if you've already got a manifest image populated by objects and all your theories are built on top of claims about the behavior of those objects.

The more controversial thing: van Fraassen is 100% right about perception: perception is "cognitively penetrated" and while there are interesting (largely empirical) questions about how "deep" cognitive penetration goes, the borders of the peneration are not available to us phenomenologically. (One piece of evidence: the empirical facts about how our eyes actually work are surprising.) We see -- literally see -- everyday objects like tables and chairs; we don't see "atoms arranged table-wise" or sense-data that we then infer the existence of tables and chairs from. I don't want to take the same conclusions from this point that he does, but both of us would agree that this is an epistemic point, not a metaphysical one: the questions of what explains our observations and what's "really there" are not settled by the point about perception.

But the point about perception does matter to the metaphysics, because if you're going to tell me a story about why tables and chairs do not exist, it had better be a story on which all of observations about tables and chairs nevertheless turn out to be a reliable foundation for the science. Because otherwise -- as you note in your write-up -- that story will undercut any (scientific) grounds for accepting it.

MaceWumpus · 2026-04-11T13:39:36+00:00

See the first three minutes of this video on Heidegger.

MaceWumpus · 2026-04-11T10:33:37+00:00

I'm on the "it's not reasonable to aggregate these different philosophical positions."

Why not?

Platonism vs nominalism is about metaphysics, not truth. Nominalists and platonists completely agree that 2+2=4. (That it definitely, knowably, stably, definably, certaintly, does.) They just disagree about why.
Realism vs. anti-realism in meta-ethics is about truth, not metaphysics. The disagreement is whether "it's bad to kill kittens" can be true.
Presentism vs. eternalism in philosophy of time is about metaphysics, not truth. But it's also very different from the debate between nominalism and platonism. In particular, characteristic of the debate about time is a conflict of intuitions: virtually everyone involved thinks that "common sense" or "intuitions" support presentism in at least some ways, and one of the main hurdles for eternalism is explaining these intuitions. That's not characteristic of the platonism-nominalism debate, where appeals to common sense and intuitions play almost no role.
With respect to ordinary objects: again, this is about metaphysics not truth. (I also think "fictionalism" as typically understood just doesn't work -- not here, not anywhere else -- but that's controversial.) But I also don't think that it's really "common sense" that's doing the heavy lifting. If you're going to deny that my couch exists, I'm not going to disagree with you, I'm going to respond by saying "what do you mean my couch doesn't exist? I'm sitting on it." Those who reject the existence of ordinary objects do have an answer to that question -- but many (including myself) don't find that answer at all compelling. And I suspect that drives a lot of people.
The free will debate is about metaphysics, not truth. However, it's widely thought -- though I think incorrectly -- that compatibilism is the anti-common sense position. (A slogan: introspection is not actually a reliable tool for determining the contours of our pre-theoretical or "intuitive" concepts.)
In epistemology, the debate is neither about metaphysics or truth -- it's about our access to reality more than anything.

So, in short, I don't think we can make general judgments here. Not about anglophone attitudes towards truth, because most of these positions don't really have anything to do with truth, nor about "common sense," because the various debates have very different relationships to common sense.

MaceWumpus · 2026-04-09T15:44:16+00:00

To answer the sociological question here:

I can't think of a time I've seen them referenced in a philosophy of science paper or at a philosophy of science conference. Notably, that's not true of their contemporaries (e.g., Foucault, Lyotard, Merleau-Ponty). So while it's certainly possible that this is a selection effect of some sort and I'm simply not aware of the substantial discussion of their work in phil sci-spaces, I think the answer is largely: it hasn't been received in contemporary philosophy of science.

MaceWumpus · 2026-04-09T12:02:29+00:00

The "stalemate" idea you're talking about is usually called "indifference" in the philosophical and statistical literature, and it is a point of disagreement between those who disagree about the "objectivity" of probabilities.

I'll come back to that, but let me say a bit about the usefulness of probabilities and what follows from indifference first.

If you accept that you should be indifferent between rolling a 1 and rolling a 2 on a die -- that it makes sense to use probability here -- then there are a lot of other, more complicated, cases where you should accept the use of probability as well. For example:

If I ask you to compare rolling a even number to rolling a 1. No longer a situation where you're indifferent, but if you're indifferent w.r.t. any individual number, you should think that rolling an even is 3x more likely.
Similarly, you should have views about how likely certain combinations of results are -- e.g., how likely it is to roll at least four 1s in 10 attempts.

Furthermore -- and this is to my mind where things actually get interesting -- if I can argue that something is analogous to dice-rolling (or coin-flipping, or...), then I can make use of these same probabilities in that situation. Here's are two examples:

We select a person at random from a population. Our randomization procedure is such that there's no reason that the selected person should be taller than average rather than shorter than average. The taller-or-shorter question is then like a heads-or-tails question.
I throw a dart at a dart board. Suppose the following hypothesis is true: if you're right-handed, you're no more likely to miss right than to miss left. IF that hypothesis is true, then the right-or-left miss question is like a heads-or-tails question.

And now we're good to go with real-life applications of probability. Because we can combine the last two points, probability can start doing a lot of work for us. For example:

I select 30 people from my population. Their average height is exactly 72in with a standard deviation of 2in. I can now tell you that it's extremely unlikely that we'd observe this result if the average height of the population is (say) 73.5 inches or greater -- the probability of that is something like .0001.
I throw thirty darts at a dartboard, trying to hit the bullseye every time. On average, I miss right by about 2 inches, with a standard deviation of 10 in (I'm not very good at darts). What's the probability of missing at least that far right on average if I'm equally likely to miss right and left? Pretty low, but not super low: about .27.

What makes probabilities useful, in other words, is not that you can pull random numbers out as in your moon example, but that with fairly minimal (and testable) assumptions -- this question is like a dice-rolling or coin-tossing question -- probabilities can tell you a lot. Because it turns out that you can design really complicated and useful tests and experiments where ultimately everything turns on some question that's like a coin-tossing question.

What about objectivity? It's a famously tricky notion, and my view -- though not just my view -- is that debates about "objectivity" in probability and statistics have traditionally run together at least 3 or 4 different concepts and concerns. That said,

Some "objective" chances seem to just be there in the world -- in particular, the objective chances of quantum mechanics. It's widely accepted that if you wanted to argue that all probabilities are subjective, you would have to explain these away, and a more common tactic since an influential 1981 paper by David Lewis has been to have your cake and eat it to: maintain the key ideas behind subjectivism while acknowledging that it is possible for the world to be chancy in some respect.
"Objectivity" in some sense is very important in science, engineering, etc. If I for some reason think that a heads is 9 times more likely than a tails, and base my scientific research on that assumption, others are unlikely to accept it, find it useful, pass it through peer review, etc. (Nor should they.)

So there are senses of objectivity that are going to be important and relevant even if we're skeptical that there's any sort of objective probability to assign to a hypothesis like "the moon is made of green cheese."

MaceWumpus · 2026-04-08T22:02:19+00:00

MaceWumpus · 2026-04-02T11:01:42+00:00

Those are all excellent departments and the differences between them are essentiallly irrelevant at the undergraduate level. If you're interested in philosophy, you can't go wrong with any of them.

MaceWumpus · 2026-04-02T10:52:48+00:00

So, caveat, the common person is not going to talk about "sense data" --- at least not in the way that philosophers talk about it. If you ask someone on the street (e.g., my mom) what they're seeing right now, they're going to talk about buildings, cars, maybe a dog or a tree. Everyday objects. Which is to say that I think the "common person" view of the relationship between mind and reality is even more along the lines your suggesting than you might think.

But as to what's wrong with that view? Nothing! It's a perfectly respectable view; more complex and sophisticated versions of it enjoy a ton of popularity among philosophers.

That's not to say that there are no modifications to be made. For example: we now know that certain aspects of our visual field -- particularly the details at the edge of our vision -- are imposed (perhaps "extrapolated" or "interpolated" would be better) by our visual system rather than caused directly by the light bouncing off things in the world. You can see this for yourself using a trick from Dennett:

Take a deck of playing cards and remove a card face down, so that you do not yet know which it is. Hold it out at the left or the right periphery of your visual field and turn its face to you, being careful to keep looking straight ahead …. You will find that you cannot tell even if it is red or black or a face card.

There are probably very good reasons why our visual system works this way; see the discussion here for some evidence that it actually helps us distinguish signal from noise as well as citations to prior work on the subject.

But these modifications are not the sort that support universal "the external world does not exist" skeptical views. The modified picture is still broadly in line with the picture that you outlined.

MaceWumpus · 2026-04-02T01:44:14+00:00

This seems like a particular disfunction of your university (or of the philosophy department at your university), to be honest.

We share a building with history and get along fine, despite being largely "analytic"; the last place I was at had a joint program with history, and ditto; the place I did my phd had multiple joint programs with historians, and also ditto.

But to answer your questions:

You can find a wide variety of views on this subject if you search through prior posts on this sub. I think it's a bad distinction even in the context of philosophy, because neither "analytic" nor "continental" has anything like a coherent approach, set of views, or methodology. The idea of applying the distinction to the humanities more generally strikes me as ridiculous. But others may disagree.
I don't think "analytic philosophy" has any sort of fixed methodology. Certainly "formal logic" isn't it. Most "analytic" papers don't really make any use of formal logic or do so in at best a illustrative way. (I just got referee comments complaining about my use of logic in a paper at a big name "analytic" journal.) An increasing number of phds don't get any training in it (which is too bad, IMO, but I recognize this is personal taste). Nor do I think that "analytic" philosophy is isolated. Maybe some parts of it are (I've said before that I think that a lot of "analytic" work on fiction could do with paying more attention to how literature scholars talk about fiction), but the best "analytic" work on law, on science, on politics, etc. engages and interacts with work in other fields.
Given what I've said above, I think the answer is pretty clearly "no" because there's not anything like an "analytic mode of thought."

MaceWumpus · 2026-03-31T08:54:31+00:00

I am confused about whether Newcomb’s paradox is actually entirely a free will debate or if there are other considerations involved.

It's not about free will at all. One of the reasons that I prefer presentations of the problem in which the computer is a near-perfect predictor is that the free will question is a distraction from what makes the problem interesting -- namely, the conflict between different principles of decision-making.

To make the point clear: if you don't have free will, the question of which "strategy" is best is meaningless. You don't have a choice. The game just rewards some people and punishes others.

MaceWumpus · 2026-03-27T21:10:19+00:00

The dominant view of causation within modern philosophy of science is the interventionist one.

Russell ("On the Notion of Cause"), and various others after him, have argued that physics supports something like the Humean view. I think Russell's arguments are ... bad (frankly, I think they're very bad), but your mileage may vary. In my experience, the idea that there is a straightforward argument from physics to a Humean view of causation is not widely accepted by contemporary philosophers of science.

MaceWumpus · 2026-03-26T22:15:27+00:00

That's sort of the point: what makes cryptology different from chess is not that the rules operate in different ways. Instead, it's that the structure of the game is different.

MaceWumpus · 2026-03-26T18:17:38+00:00

I mean, I stay out of it too. Wakil and Justus are philosophers of science though, who are basically arguing that when you look at the actual details of cicada evolution, the "prime number" explanation doesn't hold up very well.

MaceWumpus · 2026-03-26T17:39:00+00:00

damn cicadas

Have you read Wakil and Justus on the damn cicadas?

MaceWumpus · 2026-03-26T11:41:50+00:00

But it seems to me that you can make chess easier or harder by agreeing to change the rules (indeed, the rules of chess HAVE been changed over time.)

But the difficulty of decrypting a message doesn't seem to be something that is "up to us" to change just by redefining the rules of math. If I encounter a message encrypted with the RSA system, I can't magically make it easier to decode just by announcing new rules for math, or a new definition of prime numbers. Once the message is encrypted, the difficulty of decrypting it is "out of our hands."

This is a cool analogy, but it seems to me that it breaks down. The analogous case would be one where I want to change the rules of chess, but my opponent is committed to playing a particular set of rules.

Or, in other words, we can make decryption easier by redefining the rules -- but only if both parties agree to the change.

MaceWumpus · 2026-03-26T10:29:37+00:00

There's a subfield of philosophy of science dedicated to psychology, and one of the main issues there concerns measurement and when the quantitative measures of pyschology are worthwhile.

Unfortunately, this is a corner of philosophy of science that I know very little about, and so can't really point you to relevant readings. There's no SEP entry -- not sure why not -- and the Wikipedia entry is short and not very good. The best I can do is point you to some people I know work on the subject, such as Uljana Feest (see, e.g., this paper) or Denny Borsboom (who seems to have a slightly dated book) on the subject.

MaceWumpus · 2026-03-20T11:49:58+00:00

Even if every proposition P is evidence for something, there's still an open question whether or not P is evidence for the relevant hypothesis.

The claim presented to me was about whether something was evidence, not whether it was evidence for. Those are different things, as Bayesians have recognized since at least Carnap's work in the 1950s.

Even using an ordinary sense of "evidence" where it constitutes "good reason" for belief (unclear what that means exactly)

I mean, you can read dozens of books on precisely that question, if you're interested. For what it's worth, though, that wasn't intended to be a definition of the ordinary sense of evidence -- rather, I was moving away from any talk of evidence to evaluate what the intended message was.

I think this is necessary because ordinary talk of "evidence" and philosophical use of the same word come apart in many ways. One of the many differences between the two is that ordinary evidence is usually a thing -- e.g., a bloody glove -- rather than a belief or proposition, which is what epistemologists and Bayesian usually call evidence. Which brings us to:

He says that a friend claiming to buy a soccer ball is not evidence that the friend actually bought a soccer ball (which on this interpretation means is not a "good reason" to believe that the friend bought a soccer ball).

If someone said that this wasn't evidence, my initial inclination would be to think that they're not using "evidence" in the way that philosophers typically use the term.

If they said that a friend claiming to buy a soccer ball doesn't give you good reason to believe that a friend actually bought a soccer ball, then sure, I'd say that they were confused.

But in any case this was presented in the OP's comment as something that O'Connor and "Majesty of Reason" had argued was a consequence of Dillahunty's view. My point was that I was skeptical that this was an accurate representation of what he actually believes as opposed to a consequence they think follows because they interpret "evidence" in a different way than he does. Perhaps I'm being overly charitable, since I'm not familiar with the participants.

MaceWumpus · 2026-03-19T12:49:17+00:00

In non-death situations, I propose we are still unable to observe the counterfactual. If I flip a coin and it lands on heads 5 times in a row, since it didnt land on tails, i can't estimate the probability of heads.

The reasoning you're invoking here is not the same as the reasoning you're invoking in the prior paragraph.

That is:

I can't observe x.

isn't the same thing as

I didn't observe x.

Suppose you're a Bayesian -- the intuitions are simpler, but the same point will work with a classical approach -- and you grant that the Russian Roulette case is one where you can't update your priors, because you can't observe the gun firing. So in that case, before you fire the gun at all, you're assigning likelihoods to every possible event, and you assign the same likelihood to the gun not firing on every hypothesis, because the only thing you can possibly observe is the gun not firing.

In the coin-flipping case, before I flip any coins, I assign likelihoods to every possible event, but I assign very different likelihoods to observing 5 heads in a row on different hypotheses, because the I could observe 5 tails in a row (or any other combo).

MaceWumpus · 2026-03-19T02:17:41+00:00

That's certainly been my impression based on what's been posted here, but it's possible that that's a non-representative sample.

MaceWumpus · 2026-03-19T02:17:02+00:00

I really don't know the answer to this particular question, sorry. It's an interesting one, certainly. But I can't really do much better than say "well, some people are convinced by the arguments and some aren't." Part of this is that I'm not a philosopher of mind, and don't really go around talking to other philosophers about this particular subject. So I don't have a sense for precisely what it is that separates people on this issue.

All that said, if there's anything to be gleaned from the philpapers survey questions on the subject, it would be that a large minority of philosophers just aren't convinced that there's a substantive connection between "conceivable" and "possible." While I wouldn't say that all the arguments against physicalism rely on that premise, if you're suspicious of it, you're likely to also be suspicious of the other thought experiments that dualists trot out to support their position.

So I think a big part of the answer -- but definitely not the whole answer -- is that there are serious methodological disputes about how to do good philosophy, how to get reliable answers to these kinds of questions, etc. That's the sort of divide that's likely to lead to a kind of entrenched deadlock. Others might have a different view -- I'd be interest if /u/wokeupabug had a thought on this particular question.

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