Talk:Modal logics

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“Criticism of modal logic” section[edit]

@OnlySortaDumb I’m still fleshing out ideas. Hence a lot of the text will be edited down—considerably. If it waxes uncritical, then it shan’t last as such. LeucippusSalva veritate 22:06, 7 April 2022 (UTC)

Apologies, but can I request you keep criticisms relevant to serious objections such as Quine, and any responses from serious philosophers? Of course with the added Rationalwiki snark if needed. Try to avoid including personal criticisms unless vetted by an additional source, or you run the risk of presenting misunderstandings of the meaning modal operators as if they are uncontroversial accepted interpretations. - Only Sort of Dumb (talk) 22:15, 7 April 2022 (UTC)


@OnlySortaDumb You’re right about some of those edits being ludicrous (and insulting in their crudity) to ascribe to Quine. However, when I previously said that I was “fleshing out” ideas I also meant that those ideas, considering this is a draft, might be particularly clumsy. Nevertheless, those ideas were to serve as kernels that might be refined so that they could either be connected to Quine’s actual views or, perhaps, moved to a different section. I want to make it clear that I am not on some motivated crusade against modal logic—I fear that my edits (which should’ve been on the talk page) and my tone have made me appear intolerant, which I deeply regret—, I was just pursuing a dialectic and hoping to engage in debate with a user who was online and whom is more knowledgeable than I on these matters.

My comments about modal logic and theology (I should’ve included Aristotelian essentialism as well, in order to better elucidate my suspicions), for instance, were not meant as a “hot take” (whatever that is?), but as indicating a suspicion, or better yet, the belief that modal logic is ill-founded.

I’m not entirely sure what I was doing in the “Conditional logic” section—I should have criticised that within my proposed subsection: “confusing the material conditional with material implication”. Instead, I should have pursued the following line (you’ll have to tell me, whether this is more accurate?): I understand that the rule of antecedent strengthening permits one to infer from a premise that includes the material conditional (‘p⊃q’) to the conclusion ((p . r) ⊃ q). And that each statement variable within the above schemata viz. ‘p’, ‘q’, and ‘r’, may be supplanted by any statement via substitution introduction; and more importantly that the extension of each statement letter, as opposed to the what the statements appear to be about (i.e. the statements ‘Jane visits South Africa’ and ‘Iron is a metal’ are intensionally different, but both express the same truth value), is a truth value, so that the schemata may be viewed as representing a general pattern/structure of truth values. The extensionality, however, typical of classical logic, can lead to sentences in the object language that appear “unnatural”: in the case of the material conditional—which as a truth function is only false if the antecedent is true and the consequent false—one can have any true statements substituted at the occurrences of ‘p’ and ‘q’ whilst preserving the truth of the whole. What leads to the perceived “unnaturalness” is that the if-then idiom is often used in ordinary language to connote implication, or some causal relationship, whereas in the object language of classical logic it operates as a much more general entity, a truth function, which applies solely to truth values and yields solely truth values (nothing else matters—no intensional content for instance). In the case of antecedent strengthening (which seems to me to be a special case of substitution i.e. where ‘p . r’ is substituted at the occurrence of ‘p’ in the schema ‘p⊃q’) one is able to infer from an otherwise unproblematic compound to a new and more complex conditional compound which appears to accept bizarre instances. However, this bizarreness is effected by viewing the conditional through the lens of implication, a concept that is part of the metalanguage, and it doesn’t follow from the valid inference of antecedent strengthening that the former schema that is the premise implies the schema which is our contemplated conclusion. To access whether implication holds we could access whether the premise is jointly incompatible with the negation of the conclusion (I believe that by this method we will find that they are compatible and hence, per our example, that ‘Julie visits South Africa and dies at the airport’ but this doesn’t imply that she goes on a Safari.) LeucippusSalva veritate 20:32, 9 April 2022 (UTC)

From what I understand this is the most part correct, but that is why (and in part what you are alluding to) the conditional itself is not treated as interchangeable with implication. Regardless plugging the formulas into a truth table would indicate validity, and in classical logic the content of atomic sentences are supposed to be treated as irrelevant. I guess part of the confusion here from my part is if we want to assume “valid inference” and “implication” are interchangeable (which one can make the case that they very well may not be).The theology thing however seems a stretch, no academic work on modality I have read ever made this connection and the connection seems on the surface of things unwarranted. “Hot take” is colloquial to mean “controversial or unconventional opinion” as opposed to a “cold take” one that is widely accepted and hardly novel. By coming to this article with the assumption the topic is dubious or ill founded it suggests to me a bad faith motivation. It’s fine to include the criticisms by Quine however, but running with controversial philosophical views about modality (and what counts as “scientific” for that matter) as if it’s undeniably factual speaks to a bias regarding the subject that isn’t reflected by logicians or academic philosophy. (At least from the works I read and my experience in university). I don’t think we should be too dismissive then what’s warranted; that being said we shouldn't present the topic as unproblematic either. I think you and I should probably spend more time communicating with one another before making major edits so as to make an article we are both satisfied with, and reflect the basis understanding of relevant experts as per rationalwiki’s mission. Which in this case to why knowing about the subject may be of value to scientific skeptics/rationalists - Only Sort of Dumb (talk) 23:37, 9 April 2022 (UTC)
You are far more knowledgeable of the subject matter than I am; and, moreover, I am not interested enough in the topic to be of much assistance. So I suggest that you delete my additions and proceed in whatever way you see fit (in the manner you were originally proceeding, before my edits). And from your above comments, I for one, feel very confident that you can produce an article that honours this wiki’s mission. LeucippusSalva veritate 19:23, 10 April 2022 (UTC)
If that is how you feel. Though I wouldn't undervalue your contributions too much. The Quine criticism is still relevant to the topic and rationalwiki's mission. I have practiced modal logic and own several books on the subject but I am not too confident with my competence and I am partially relying on the contribution of others who I assume to be more knowledgeable than me to expand on what I write. I appreciate your self awareness and humility, and you are still welcome to edit if you ever change your mind. - Only Sort of Dumb (talk) 23:41, 11 April 2022 (UTC)


What is the relationship between modal logics and postmodernism, if any? Bongolian (talk) 20:26, 16 April 2022 (UTC)

I would not say that there is a connection. 𝒮𝑒𝓇𝑒𝓃𝑒 talk 20:38, 16 April 2022 (UTC)