But we are substituting this into an opaque context - whether they are empirical facts. — Banno
If you want to use logical shorthand, we have P = V, H = V, therefore P = H. Regardless, there was a time when it was a fact this thing in the sky was called P, and there was a time when it was a fact this thing in the sky was called H, and in these times, P was not known to be H. At some later time, experience informed that P, H and V were all the same thing in the sky, P = V at one time, H = V at a certain other time relative to the first time. After that, after the facts changed due to new experience, the thing in the sky was just V.
P never was equal to H, the proposition P is H never occurred to the Greeks, as Kripke said of something else and thus misspoke**, “surely no amount of
a priori ratiocination on their part could have conceivably made it possible for them to deduce P is H”, so why are we belaboring the nonsense of it now?
** He said it of astronomers who discovered the distinction, when he should have said it of those who never considered there was one. Besides, one needs no
a priori ratiocination when he’s got a telescope and a camera.
So it seems we are left with empirically discovered necessities. — Banno
Ehhhh…..maybe. I’d say we have empirically discovered relations, the relations we understand as being so because they necessarily conform to the laws we invent to describe them.
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WHere's the argument? — Banno
In the text, which as you must well know, is a convoluted mess, requiring some presuppositions, and wouldn’t benefit this discussion.
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Knowledge is experience, experience is always changing with time, so knowledge is always changing with time, therefore knowledge is contingent on time.
— Mww
Well, we know 4=2+2, but that doesn't change over time... an we know water boils at 100℃, at any given time; that doesn't change. So that doesn't work. — Banno
By “knowledge is experience”, the term knowledge is tacitly understood to be empirical knowledge. Mathematical propositions are not empirical knowledge in their construction, but only in their proofs. Mathematical propositions change over time only insofar as the system that constructs them changes; the human cognitive system that constructs mathematical propositions hasn’t changed so the propositions won’t change.
We knew once a liquid substance; we knew later a liquid substance we deemed to label water; we knew later the liquid substance we deemed to label water, boiled; we knew later water boiled at 100C, we knew later water boiled at different temps relative to pressure. Hell, we knew later, not only do things float in water, but water itself floats!!! How cool is that?? Knowledge changed over time.
We didn’t know water boils at 100C at any given time, as you say, until we learned at one time water boils at 100C. We know
post hoc and
a priori, as mere inference, water under a certain set of conditions will always boil at 100C. Just like, because you put it there at one time, you know
a priori that stupid cup is still in the stupid cupboard at any other time, as long as nothing happened to alter the initial conditions.
It is possible the set of conditions under which water boils at 100C changes, such that water no longer boils at 100C. Some would like to proffer that this is sufficient reason to claim physical law is tentative, and in so doing, imply human intelligence is schetchy at best, insofar as it is human intelligence alone which determines physical law. Which is tantamount to those some slapping themselves in the face, getting nothing from it but a ruddy cheek.
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Kant and Kripke. There is obvious disagreement, but they are doing different philosophies, so no big surprise there. The idea was probably, if Kant was brought into this era would he find current philosophy noteworthy. While it is patently unjustified to speak for him, personally I think he would find it unapologetically superficial, there isn’t a particular philosophical doctrine these days a majority of thinkers support, and, there’s a conspicuous dearth of cognitive metatheories.
Nowadays, people who philosophize at all are apt do so regarding what’s said and its communal effect, rather than what is thought and its private effect, and his
magnum opus concerned the rational subject over the empirical object, and even with the spectacular advances in physical science, the rational subject is still pretty much just as he was in the 18th century, so I think CPR would be written pretty much as it was. His other sciency stuff would probably be different, and there’s reason to suppose he might have come up with stuff that set the tone for other scientists, just as he did on the 1700’s.
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might be of further interest to Mww.
That this table is not made of ice is known a posteriori - by examining the table. Yet that this table is not made of ice is a necessary fact about this table - if it were made of ice, it would not be this table. — Banno
All that’s fine, but what’s the point? That this table is made of this substance immediately precludes it being made of any other substance. I rather think that if this table is made of, say, wood, wood isn’t so much an essential property, as being a given property. It would seem the essential property of a table is merely is spatial extension, its shape, without regard to the substance of its construction.
Of more import, methinks: Kripke says, “…this table, if it exists at all…”. If he talks of a table, isn’t its existence given? Otherwise, shouldn’t he be talking of a possible table? Minor quibble, one of many, and overall, irrelevant, other than to exemplify differences in philosophical ground.
Then he says, “this table
if it exists art all was not made of ice is necessary…”. Taken as a complete sentence, shouldn’t that have been “…was not made of ice is necessarily true”? Continuing, and under the assumption he means necessarily true, he says, “was not made of ice is necessarily true, it is certainly not something we know
a priori”.
Hmmmm…..I don’t think that’s quite right. He’s asking about what we know. So we have a thing we know, a table, made of something we know, say, wood, so we can
say with certainty it is not made from anything else, but the ask concerns only what we know, not what we can say.
(Recall the quote, “ Experience no doubt teaches us that this or that object is constituted in such and such a manner, but not that it could not possibly exist otherwise…”)
Experience cannot tell us the table could not have been made of something else, but if it is necessarily true it couldn’t have been made of anything else, because it isn’t, we must have known that
necessity a priori.
It isn’t that we know it isn’t made of ice, it’s that we know it is necessarily true it isn’t made of ice. Given that there are only two ways for a human to know anything at all, experience and reason, and the former is from experience but the latter is not, therefore the knowledge in question must be from reason alone, which is, of course,
a priori.
I’m not going to apologize for the length of the post. Peruse or not as you wish.