It was my understanding that questions concerning formal logic (classical, propositional, predicate, etc.) were welcome in the Philosophy SE. Counter to my intuition, this question regarding how to formulate an inference rule from in tautological form was put on-hold as "off-topic", with the official reason "the question itself doesn't seem to be about philosophy, and is therefore not a good fit for our site."

Are technical questions in logic not welcome here? Sometimes I post questions in mathematical logic over at the Math SE, but I honestly appreciate the more philosophical perspective of the philosophers and logicians here, something I take into consideration when deciding whether to post at Math SE or Philosophy SE. It's not clear to me which questions are only welcome at Math SE and not here. The notion of where logic ends and mathematics begins is undecided in the academic community. For instance, does propositional logic belong to Philosophy, and predicate logic belong to Mathematics? What about sequent calculus? I suspect any hard line one attempts to draw would be disputed by those on both sides. I, personally, would have a hard time delimiting the boundaries of each discipline.

The impression I gathered from this post, however, is that technical questions are welcome in both philosophy and mathematics SE:

In the end, I believe that many logic questions could be asked either here or on the mathematics sites. If you ask a logic question here, it seems that you are more likely to get an answer with a greater level of philosophical gloss, with philosophically oriented examples, for example; and if you ask on the math site you will get an answer with greater level of mathematical gloss and mathematical examples. So my advice is to ask in the forum that appeals to you. But don't shy away from asking technical logic questions here, since there are people here who are interested and can answer.

Answers to the question Is "Stack exchange is not the place to learn first order logic" a correct statement? seemed to echo similar sentiments: that SE is a platform for "learning together" and specific questions about first-order logic are "absolutely on-topic".

Does Philosophy SE have an official policy on which questions in logic are excluded to Math SE? How is it decided which questions are too technical (or insufficiently "philosophical") to be deemed on-topic at Philosophy SE?

  • Hey, the closure might've been somewhat perfunctory here -- I was in cleanup mode on the review queues. Please try to narrow down the question and specify as closely as possible what exactly you would like someone here to explain to you (ideally with reference to some specific philosophical context.) I'd be happy to review reopening
    – Joseph Weissman Mod
    Commented Feb 10, 2017 at 3:43
  • 1
    @JosephWeissman I do appreciate the cleanup work, but in this case I'm not sure I see the point in closing a question with an already accepted and upvoted (and overall quite good) answer. Even if the question could be a little more focused, I think the answer shows that the matter is on topic.
    – E...
    Commented Feb 10, 2017 at 10:04
  • Sure, reopened.
    – Joseph Weissman Mod
    Commented Feb 10, 2017 at 15:09
  • Thanks @JosephWeissman ! Commented Feb 11, 2017 at 17:09

1 Answer 1


It depends on the logic.

For mathematical and computational logic, and really anything having to do directly with numerical systems, I think math is entirely appropriate.

If the logic question is essentially non-numeric in nature, philosophy it is.

But to be fair, there is a lot of crossover, because strong logic in any field can be translated to strong logic in any field with enough familiarity. If it works in both fields, great! If it really doesn't seem like math, I'm happy with seeing the question in Philosophy.

There are computational logic questions that might be better addressed someplace like Stack Overflow, OOP SE, etc., and so really it's not a matter of "all logic fits into one category" in any case.

It's something that requires a bit of subjective judgment, and I really am left a little disheartened by the quickness to downvote and/or close things as "off-topic" when it really does relate at a fundamental level.

I'm in favor of allowing "newbie" questions, because if someone can't answer something to the satisfaction of a newb, they don't know the topic well enough (a rough paraphrasing of Einstein's quote).

Simplicity is often overlooked. I think there's not enough of it in the world.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .