1 of 1- Due_Kindheartedness
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Tautologies and the Is-Ought Problem
I was inspired to ask this question by a line in the anime Haruhi Suzumiya: "Summer should be like summer, so we have to do summery activities."
The statement "summer is summer" is a tautology. But I'm not sure if the statement "summer should be summer" is in fact a tautology. Is it, in fact, a tautology, and why?
- Greg
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Re: Tautologies and the Is-Ought Problem
Tomislav Ostojich wrote:
The statement "summer is summer" is a tautology. But I'm not sure if the statement "summer should be summer" is in fact a tautology. Is it, in fact, a tautology, and why?
I am not sure that even "summer is summer" is a tautology. You could not, I think, infer it from an empty set of premises in first-order logic with identity.
It is true, if "summer" is a referring expression. But statements of the form "a is a" are false or non-referring when "a" does not refer, as in "Flubwoggle is Flubwoggle".
Given the truth of the law of identity and the existence of summer, you can conclude that summer is summer. If you had a law paralleling the law of identity, only for oughtness, then you could conclude that summer should be summer. In some readings of "summer should be summer," though, the modality of the "should" is probably more like natural necessity; the more plausible reading (from what you are reading) is probably that "summer should be like summer" means "we ought to behave as though it is summer".
- Due_Kindheartedness
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Re: Tautologies and the Is-Ought Problem
the modality of the "should" is probably more like natural necessity; the more plausible reading (from what you are reading) is probably that "summer should be like summer" means "we ought to behave as though it is summer".
There's an ambiguity in the English language (in fact, it is a linguistic universal that all languages share this ambiguity) between the deontic sense of the word "should" and the epistemic sense of the word "should." You are interpreting my post with the epistemic sense of the word "should," when I am using it in the deontic sense.
When we say that "summer should be summer," are we saying that "of all the possible things summer could be, in the best possible world, summer is summer"? Let's suppose that there exists some "summer+" where instead of being like your typical summer in a continental climate with warm weather, "summer+" also causes all sentient inhabitants of the season to experience warm, pleasant nostalgia. Would it be better for summer to be more like "summer+," or instead to be like plain old summer? If it is better for summer to be like "summer+," then can we truly say that "summer should be like summer" when, instead, it should be like "summer+"?
Sorry if this seems terribly confusing, but I don't know how can I explain my thought in a clearer manner.
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Thread Starter- Greg
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Re: Tautologies and the Is-Ought Problem
the modality of the "should" is probably more like natural necessity; the more plausible reading (from what you are reading) is probably that "summer should be like summer" means "we ought to behave as though it is summer".
There's an ambiguity in the English language (in fact, it is a linguistic universal that all languages share this ambiguity) between the deontic sense of the word "should" and the epistemic sense of the word "should." You are interpreting my post with the epistemic sense of the word "should," when I am using it in the deontic sense.
Do you have examples? I suspect there are many senses of "should", though I'm not sure I know what you mean by the epistemic sense. Does "dogs should have four legs" use "should" in the epistemic sense?
I recognize that the original quote you gave probably uses it in the deontic sense, though I think that requires rereading it in terms of what "we" (or some agent) should do. I think "summer should be (like) summer", read literally and with "should" in the deontic sense, is nonsense, like saying "dogs morally ought to have four legs". I think the deontic sense requires an agent.
But in any of the cases, it is not a tautology.
Last edited by Greg (5/07/2016 9:59 pm)
- Due_Kindheartedness
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Re: Tautologies and the Is-Ought Problem
Do you have examples? I suspect there are many senses of "should", though I'm not sure I know what you mean by the epistemic sense. Does "dogs should have four legs" use "should" in the epistemic sense?
"Easter should land on a Sunday" uses the modal verb "should" in an epistemic sense. "You should be nicer to Bobby" uses "should" in a deontic sense. "Dogs should have four legs" uses "should" in an epistemic sense.
I recognize that the original quote you gave probably uses it in the deontic sense, though I think that requires rereading it in terms of what "we" (or some agent) should do. I think "summer should be (like) summer", read literally and with "should" in the deontic sense, is nonsense, like saying "dogs morally ought to have four legs". I think the deontic sense requires an agent.
But in any of the cases, it is not a tautology.
Let me put it to you like this: dogs are clearly designed to have four biological legs. However, what if a group of transdoganists concluded that dogs would have a better functioning with prosthetic legs? Then is it the case that a dog really should have biological legs?
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