cognition — KantDane21

Perhaps "perception" would be a more suitable word than "cognition" in this situation. Cognition implies an active act of manipulating concepts. Perception implies a passive observation.

"Either all cognition is cognition of appearance, in which case there can be no cognition of noumena, or there can be cognition of the noumenon, in which case cognition is not essentially cognition of appearance"

P- all cognition is of appearance.
Q- [there can be] cognition of noumenon. — KantDane21

(P ∧ -Q) ⋁ (Q ∧ -P)

(Not an argument)

My logic is very rusty, I have given it a shot below, but not sure if it is correct. feedback appreciated!

"Either all cognition is cognition of appearance, in which case there can be no cognition of noumena, or there can be cognition of the noumenon, in which case cognition is not essentially cognition of appearance" — KantDane21

Honestly I'd render this as "P or not P" where..
P = There cannot be cognition of noumena
or
P = All cognition is of appearance

If cognition applies to appearances only, then cognition does not apply to the noumena.
If cognition applies to the noumena, then cognition does not apply to the appearances only

Maybe in the wider context it's different, but I wouldn't call this sentence an argument as much as a clarification or a definition of two mutually exclusive beliefs (at least according to Kant)

"Either all cognition is cognition of appearance, in which case there can be no cognition of noumena, or there can be cognition of the noumenon, in which case cognition is not essentially cognition of appearance" — KantDane21

As regards cognition, it is not a case of either-or, in that I can both cognize about appearance and cognize about noumena, such that P ˄ Q is possible.

Cognizing about an appearance and cognizing about something that caused the appearance are not mutually exclusive.

Although I can cognize about the concept of noumena, because, by the definition of noumena, I can never perceive noumena in the world, I can never cognize about particular noumena.

A = x is cognizable, B = x is a noumenon (and ~B = x is an appearance)

1. (A → ~B) v (A & B)
2. (A → ~B) v ~(~A v ~B)
3. (A → ~B) v ~(A → ~B)
True

Not sure what everyone else is doing, or what your P and Q lead to, but the argument is obviously right and I think this is the simplest way to formalize it. (We could do quantifiers and stuff, but it's really simple.)

My way is cleaner than yours because my sentential variables are really pretend predicates, just leaving off the variables. That means we don't stuff quantifiers (like 'all') into the variables.

The main thing is to render 'All F are G' as 'F → G'; that is, read it as 'If something is an F, then it's a G.'

The only other rules used were de Morgan's law to get from (1) to (2), and then the equivalence of P → Q to ~P v Q to get from (2) to (3). Or you can just recognize that if something is both A and B, that means being A doesn't imply not being B.

And then we're done, because (3) is a tautology, so (1) is valid.

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My logic is very rusty, I have given it a shot below, but not sure if it is correct. feedback appreciated!

"Either all cognition is cognition of appearance, in which case there can be no cognition of noumena, or there can be cognition of the noumenon, in which case cognition is not essentially cognition of appearance — KantDane21

As far as I know cognition of how something appears is as much to do with the perceiver as it is to do with the object being observed.

Consider an extreme case: whereby a colour blind person percieves green and red to appear both as similar greyness.
Cognition of appearance is grey for such people but does that mean the object is really grey? Others (non colour blind) would argue for varying shades of red and green.

So therein you have cognitive dissonance pertaining to the same object of observation. So it's clear that perception and cognition alone is not necessarily absolute.

Noumena on the other hand is the innate character of an object regardless of observer. In this sense scientific approach is useful as it can address what is objectively the case. It can measure the wavelength of light reflected by the object which could be predominantly 700nm (typically observed as red) and 520 nm (typically registered as green).

So here we have a dilemma. We have two people - one of which is colour blind, looking at the same object and interpreting it's characteristics differently. Who then is correct?.

Well they are both correct in reference to their individual capability to perceive the object. However the noumena of the object is neither case. It is just reflecting wavelengths of light. Wavelengths of light don't in themselves impart colour. Colour as a quality is subjective in such a case.

Just as we can't look at a lemon and identify that it releases predominantly 575nm wavelengths of light. Which it does based on objective measurement but not based on perception. A severely depressed person with no sense of the vibrancy of life may perceive a desaturated cold grey lemon devoid of any joyous/ jubilant yellow, while another could see more tones of yellow than anyone else.

We therefore can trust science to give an exacting standard while contrarily we cannot assume our own interpretation matches such an exacting standard. Otherwise we could look at any colour and describe its discrete wavelength simply by individual observation.

For me I thought of the "in which case" clauses as having the P xor ~P "distributed over" them, emphasizing the "Either" at the beginning, and these were functioning like a definition of terms.

So if P then Q, xor if ~P then R
Q = "in which case there can be no cognition of noumena"
R = "in which case cognition is not essentially cognition of appearance"


But it's confusing to me because of the words "there can be" and "not essentially", and then they both read like restatements of the original position -- if all cognition is of appearances, in that very case there can be no cognition of noumena (since noumena aren't appearances), whereas if cognition is not only applicable to the appearances, then in that very case cognition applies to more than the appearances (i.e., it is not "essential" to it).

At least, that's what I was thinking in reducing it to a simple P or not P. Maybe it's too simple, though. (I agree with your rendition, too, just felt the need to explain my thought process)

1. (A → ~B) v (A & B)
2. (A → ~B) v ~(~A v ~B)
3. (A → ~B) v ~(A → ~B)
True — Srap Tasmaner

Many thanks all the replies! very helpful!

one thing, in this argument (as such) we are dealing with an exclusive disjunction right??
Thanks again!

(1) is valid — Srap Tasmaner

I cognize something x. Cognition is a higher level function of the brain. I can cognize about x both as an appearance and a noumenon.

As regards cognition, then why not A → (~B ˄ B) ?

This also follows the two-aspect interpretation of Kant's Transcendental Idealism.

(deleted)

one thing, in this argument (as such) we are dealing with an exclusive disjunction right?? — KantDane21

Well,

(P ∧ -Q) ⋁ (Q ∧ -P) — bongo fury

isn't an argument but does imply the exclusive disjunction of P and Q. (Denying their conjunction.) Whereas

1. (A → ~B) v (A & B)
2. (A → ~B) v ~(~A v ~B)
3. (A → ~B) v ~(A → ~B) — Srap Tasmaner

is an argument but doesn't imply the exclusive disjunction (doesn't deny the conjunction of P and Q). Rather, it takes that denial for granted:

B = x is a noumenon (and ~B = x is an appearance) — Srap Tasmaner

But yes, mutual exclusivity of P and Q is needed to get from

P ⋁ Q — KantDane21

to

P→ -Q
Q→ -P — KantDane21

I cognize something x. Cognition is a higher level function of the brain. I can cognize about x both as an appearance and a noumenon. — RussellA

That may be, but in the quote given, there's no as-ing of the object of cognition.

(doesn't deny the conjunction of P and Q). Rather, it takes that denial for granted: — bongo fury

I did longer versions of this where I included it as a premise: 'If x is an appearance, then x is not a noumenon' — I think the conditional was all that was needed, not a biconditional, for what it's worth.

restatements of the original position -- if all cognition is of appearances, in that very case there can be no cognition of noumena (since noumena aren't appearances) — Moliere

Anyway, I think @Moliere has the right idea: there's no argument per se going on here, but an explanation of terms. Kant isn't establishing a result, just clarifying.

We often say things like this just to make clear what would and what wouldn't count as a counterexample, for instance: Either all cars are Toyotas, or there is something that is a car and is not a Toyota. It's not obvious to people who do don't do FOL all day that the opposite of a conditional is a conjunction, but it is. It sounds right, sure, but is it logically valid? Yeah, it is.

Is that what Kant is doing? Am I on the wrong track?

Either all cognition is cognition of appearance, in which case there can be no cognition of noumena, or there can be cognition of the noumenon, in which case cognition is not essentially cognition of appearance — KantDane21

Is he, for instance, arguing that cognition is essentially cognition of appearance? How could he be, since one of the disjuncts says that it isn't?

As I said, we could do this up more completely with predicates and quantifiers, we could even throw in some modal operators to cover 'essentially', but I think all that's overkill. It's a simple passage, and @KantDane21 was just a little confused about its basic logical form.

Now if we wanted to try to handle @RussellA's suggestion that there is 'cognition of x as F', and that's what's at stake here, that looks like the sort of thing classical logic is really crappy at. There's no 'as' operator because that suggests predicate interpretation, which suggests fiddling with the domain in the middle of an argument, which I guess you can do without going all dialethic, but what's the point? (I'm thinking of simple stuff like 'x is short for a basketball player but tall for a man'. You can give a semantics for 'short' and 'tall' relative to a population and thus allow someone to be short in one sense but tall in another, if that's something you really need.)

Another route would be to note that Kant is apparently making a point about cognition, rather than about which objects fall into the class 'noumenon' and which 'appearance'. So we could instead define type of cognition (again, awkward for FOL but doable), something like this:

If x is a cognizing, then x is an a-cognizing (that is, cognizing something as an appearance).

We could, again, do it all up with quantifiers, but in essence all we want to say is this:

Either all cognizing is a-cognizing, or some cognizing is n-cognizing.

And the intent there is to leave room for the same 'object' to be a-cognized and n-cognized. But it is still implied here that a-cognizing and n-cognizing are disjunct 'mental events' or types of cognizing.

And again I take it that the point of passages like this is just to clarify what the denial of the conditional would amount to logically, what we would need to show as a counterexample.

Another route would be to note that Kant is apparently making a point about cognition — Srap Tasmaner

The OP proposes: "Either all cognition is cognition of appearance, in which case there can be no cognition of noumena, or there can be cognition of the noumenon, in which case cognition is not essentially cognition of appearance"

I am unsure whether the intention is to put the above passage into first order logic as it stands independently of Kant or into first order logic such that it agrees with Kant's philosophy.

Because it seems that the above passage does not agree with Kant's philosophy, in that he wrote in Critique of Pure Reason: "we can have cognition of no object as a thing in itself, but only insofar as it is an object of sensible intuition, i.e. as an appearance."

Of course, as an exercise it can still be put into first order logic regardless of Kant's philosophy.

As an aside, even though Kant argued that there can be no cognition of noumena, there can still be cognition about noumena, as this thread attests.

Is that what Kant is doing? Am I on the wrong track? — Srap Tasmaner

I'm also curious about the context now. Do you have a citation @KantDane21 ?



Eh, I think that Kant's use of "cognition" isn't that loose. A cognition is not merely to think of something, but rather to think of something within our faculties -- so we have concepts and intuitions(intuitions, itself, is a very specialized term within Kant's philosophy too), and noumena fall outside of both of those -- we can put a sentence together that looks truth-apt, but because of our faculties being what they are we are unable to judge that sentence. Hence, we cannot cognize the noumena "The soul is immortal", though we can posit it and desire to know its truth value.

I am unsure whether the intention is to put the above passage into first order logic as it stands independently of Kant or into first order logic such that it agrees with Kant's philosophy. — RussellA

I understood the issue in the OP to be the logic of the quote, whether it's Kant or not. Everyone else seemed to assume it was Kant, so I did too. Maybe a mistake, but not relevant to the logical question.

I still find the quote pretty straightforward, but only if you're comfortable with the logic.

Ah, you're right. There wasn't a citation, even. Alas, reading is theory-laden, even on a forum post.

I'm also curious about the context now. Do you have a citation KantDane21 ? — Moliere

it is by a English Philosopher called Patrick Gardiner, will try to find exact place where he said...

I think that Kant's use of "cognition" isn't that loose. — Moliere

:up:

Almost certain the quote is in "The Nature of Historical Explanation (1952)"....skimming through now to find!

"Either all cognition is cognition of appearance, in which case there can be no cognition of noumena, or there can be cognition of the noumenon, in which case cognition is not essentially cognition of appearance" — KantDane21

In the spirit of Aristotle. Either all men are wise, in which case, of necessity there are no foolish men; or it is possible that there are foolish men, in which case it is not necessary that if one is a man then one is wise.

It implies an additional premiss. 'It is not possible that a man is both foolish and wise.' Or, translating back, 'nothing can be both appearance and noumenon.'

But yes, mutual exclusivity of P and Q is needed — bongo fury

That's the implied premiss.