I read that some thinkers (or maybe "thinkers") claim that there is such thing as "contingent a priori truth", allegedly contradicting Kant's claim. Ok here's the example I found:
This is obviously false to me and I have a hard time to understand how these people can be taken seriously. Nevertheless, I would like to know sensible opinions regarding this matter, and possibly examples that are not flawed, in case I'm missing something.Some philosophers have argued that there are contingent a priori truths (Kripke 1972; Kitcher 1980b). An example of such a truth is the proposition that the standard meter bar in Paris is one meter long. This claim appears to be knowable a priori since the bar in question defines the length of a meter. And yet it also seems that there are possible worlds in which this claim would be false (e.g., worlds in which the meter bar is damaged or exposed to extreme heat).
Here's my reasoning why that bar example draws a false conclusion: it is asserted that it is an a-priori truth because the meter is defined as the length of that bar, no problem here. But the claim that there are hypothetical cases when it is false fails, because no matter how long that bar is, it will still define a meter - because that's the definition. When the bar corrodes to the half if its length at the time the convention was made, then the new meter unit will simply be half of old one, there is no way to invalidate this fact, as long as the definition stands in place.
Now some try to argue that it is "obvious" that the bar can't stay exactly one meter long in different worlds. You can prove that by cutting a stick or a wire to exactly one meter and come later to measure the rod by it. Well, first of all, when you decide that the reference (the definition) of the meter is the length of that stick/wire, you basically redefined the meter, as the length of that object - that is now the a-priori truth which is in fact necessary. If you now measure the original rod, no matter what length it will be, your finding will be a a-posteriori type of knowledge, and therefore being contingent is consistent with Kant's view.
This case of "transferring" the definition and measuring, but also the idea claiming that you "intuitively know" that one meter is not exactly the length of that bar are anyway not applicable to the first definition, it's just a gross and outrageous relativism: the definition was initially understood as "the length of the bar defines one meter". Basically to claim that "one meter is a fixed dimension in all worlds" and "one meter is the length of this bar" are equivalent, one must use an additional assertion in the first place: "the bar has a fixed dimension in all worlds", which is incorrect and not accepted as truth from the start.
Edit: note that the literal statement in the example, "the standard meter bar in Paris is one meter long" is actually a-posteriori, unless it is acknowledged that it means - and is therefore replaced by - "the bar in question defines the length of a meter".