There is a difference between knowing the key is on the desk and being certain that the key is on the desk.
That's kinda the topic of On Certainty.
The justification for a claim to knowledge is the answer to "How do you know?" It will not do here to simple repeat your claim - I know the key is on the table because the key is on the table; I know this is a hand because it is a hand.
This is what is being said in the first few pages of On Certainty. Moore is unjustified in claiming that he knows this is a hand. Yet, it is true that this is a hand; and he is certain that this is a hand. The remainder of the book is an exploration of this oddity. — Banno
You’re making Wittgenstein’s point for him. He sees Moore’s raising of his hand as a performance which is grounded in a picture of the world which cannot be proved more correct than any other. To doubt the truth of this picture is to substitute a different picture, a different language game, just as doubting the picture of the world implied by the rules of chess is to no longer be playing chess. Moore’s demonstration convinces doubters of its certainty by bringing them to look at the world in a different way, not by satisfying them of its correctness. — Joshs
If Moore knows, that would mean there's a sense of "know" that amounts to being unable to doubt. And per Hume, you can't prove what you can't doubt. So Moore would have some kind of unprovable knowledge, which doesn't sound right. — frank
assume this is directed toward me, so I'll respond. We know that much of what Witt was saying was directed at Moore's propositions in his papers Proof of an External World and A Defense of Common Sense, so we're referring to specific propositions that Moore says he knows. Moore believes he has a justification for claiming to know "This is a hand (as he raises it to the audience)." Witt resists this notion, although he starts OC with, "If you do know [my emphasis] that here is one hand, we'll grant you all the rest (OC 1)." It seems clear to me that when Witt refers to hinge propositions or Moorean propositions he's saying that you don't know what you think you know, viz., Moore's use of the concept know doesn't apply because these statements don't fall within the domain of JTB. We don't normally justify these basic beliefs or Moorean statements. There are of course exceptions to this general rule (generally we don't justify them) and Witt points these out. — Sam26
Things capable of being seen as red are those with physical surfaces reflecting the appropriate wavelengths of the visible spectrum. A capable creature is one capable of detecting and/or distinguishing those wavelengths. — creativesoul
If Gellner's criticism is that Austin and Wittgenstein are using a term without antithesis, then he has simply failed to read and understand what is going on in each case.
Which is, indeed, the usual response to his work. — Banno
There is no color in light. Color is in the perceiver, not the physical stimulus. This distinction is critical for understanding neural representations, which must transition from a representation of a physical retinal image to a mental construct for what we see. Here, we dissociated the physical stimulus from the color seen by using an approach that causes changes in color without altering the light stimulus. We found a transition from a neural representation for retinal light stimulation, in early stages of the visual pathway (V1 and V2), to a representation corresponding to the color experienced at higher levels (V4 and VO1).
I don't know what you're talking about. — Michael
That's it. You are reading something into my words that just isn't there. — Michael
When Michael says that colors are percepts or that we only ever see percepts and never colors, he is in a very real sense committing himself to the position that we only ever see colors indirectly. — Leontiskos
I don't have a copy of Searle, but according to this:
Searle presents the example of the color red: for an object to be red, it must be capable of causing subjective experiences of red. At the same time, a person with spectrum inversion might see this object as green, and so unless there is one objectively correct way of seeing (which is largely in doubt), then the object is also green in the sense that it is capable, in certain cases, of causing a perceiver to experience a green object.
This seems to be arguing that colours are mental phenomena and that the predicate "is red" is used to describe objects which cause red mental phenomena. — Michael
Newton: "For the Rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that Colour." — Michael
The topic is about perception, not grammar. — Michael
On colour, Quine has said this:
But color is cosmically secondary. Even slight differences in sensory mechanisms from species to species, Smart remarks, can make overwhelming differences in the grouping of things by color. Color is king in our innate quality space, but undistinguished in cosmic circles. Cosmically, colors would not qualify as kinds.
Your quote of him is him arguing for eliminative materialism, which I have previously accepted is a possibly correct account of so-called mental phenomena (e.g. pain just is a type of brain activity, and so colours just are a type of brain activity.
Indeed, Quine goes even further say that colours are “neither natural kinds nor any significance to theoretical science.” But if this is the case, why not eliminate this talk of mental percepts of colour, this is not what science is investigating.
— Michael
Russell is not saying what (I think) you think he's saying. When he says "the sensation that we have when we see a patch of colour simply is that patch of colour" he is saying that colour just is that sensation. — Michael
I don't care about how Wittgenstein viewed perception and colours. He was not a physicist or a neuroscientist and so he didn't have the appropriate expertise. To think that somehow an examination of language can address such issues is laughable. Do you want to do away with the Large Hadron Collider and simply talk our way into determining how the world works? — Michael
Notice no mental percepts needed
— Richard B
Of course they are, else you wouldn't be seeing anything; you'd just have light reaching your eyes and then nothing happening, e.g. blindness or blindsight. — Michael
But not only a percept.
Where are these percepts to be found? — Banno
Claiming that they do not "really" have these colours is a misunderstanding of the nature of colour.
— Banno
No, claiming that they really have these colours is a misunderstanding of the nature of colour. — Michael
Pragmatism instead is a positive alternative in being based on a willingness to believe - and then test. Belief becomes an inveterate habit if it keeps passing the test. And that same evolutionary credo explains reality as a whole. — apokrisis
No, that is our disagreement. We agree we perceive the pen as red. Maybe you think the pen is actually red, but I don't.
— Hanover
Ok. So for Hanover, "the pen is red" is not true. I think it is. — Banno
I believe in a God who is Omnipresent, Omniscient, and Just (by Just I mean It delivers Good and Evil in the right proportion). Therefore, I think that life is Just. — MoK
The "common-sense" naive view falsely posits that colours-as-we-experience-them are mind-independent properties of objects, but the science shows us that they are not; they are mental percepts related to neural activity in the visual cortex. — Michael
don't think the OP, for example, is asking if atoms reflecting light is mind-independent. He's referring to the mental percept and asking if it's a mental percept or (as the naive colour primitivist believes) something mind-independent. — Michael
We can use the adjective “red” to describe a mind-independent pen that has properties that are the cause of red colour percepts. But the noun “red” refers to that colour percept, not a mind-independent property of the pen. — Michael
As such there is no (visible) light to stimulate the rods and cones in our eyes, and so the V4 neurons are not fired, and so no colour percepts are produced.
It’s certainly not the case that black is some mind-independent property of objects that is seen by the absence of (visible) light. That just makes no sense at all. — Michael
Disdain for scientific metaphysics: talk about material substance, naturalism or physicalism, as if these were primordial concepts. — Constance
I haven't said that mental phenomena aren't just particular brain states. I'm not necessarily arguing for any kind of dualism. I'm leaving that open. Maybe pain just is the firing of C-fibers, as Churchland argues. Maybe colours just are the firing of V4 neurons.
Regardless of what mental phenomena are, pain and colours are mental phenomena; they are not mind-independent properties of fire. — Michael
One's sees the same in Quine: "there’s mystery at the bottom of every question ultimately." When the priority is science and clarity at the level of basic questions, one finds Quine's indeterminacy staring back at you, and there is the abiding Kantian making way for faith through a kind of apophatic method of seeing where thought has its limitations. I have always had contempt for this kind of thinking, and I don't think Wittgenstein is right to dismiss ethics and value from meaningful philosophy, which I think addresses your thoughts. Analytic philosophers, at least in Quine's time, really did have that "What indeed has Athens to do with Jerusalem" style of Fideism, and Witt has been said to be just like this. — Constance
Yes. Mental phenomena are either reducible to brain activity or are caused by brain activity. We dream/hallucinate/see (in colour) when the visual cortex is active. — Michael
Again, this is the only way to make sense of dreams, hallucinations, synesthesia, and differences in colour perception – all of which are real. — Michael
"Family resemblances" is not an "idea" or "theory" that can be proved wrong. It's a vague metaphor that one could call "true" so long as there are any shared similarities between whatever one considers to be a "language-game," (which is also a term that is left vague). — Count Timothy von Icarus
I am saying "this level of vagueness is no longer necessary or helpful; there now exist ways to describe similarities in languages, animal communication, and codes with much more rigor—to actually say something beyond the trivial and banal." — Count Timothy von Icarus
*And I should note that plenty of Wittgensteinians make admirable attempts to dispell the vagueness, even at the risk of theories that sound wildly counterintuitive and implausible. It is only a certain type that seems to really thrive on the vagueness and the ability to avoid error by never really saying anything of substance. — Count Timothy von Icarus
One has to understand ethics as Wittgenstein did in the Tractatus. See also the Lecture on Ethics and his Culture and Value. Apparently this is hard to see, as is made clear by all of the Wittgenstein fans at this forum, who entirely fail to understand this basic point: ethics and value are transcendental. See what he says: — Constance
You can see why Witt's positivist friends could never understand what he was talking about. He was a deeply religious philosopher as he realized that this dimension of value in our existence is utterly transcendental and yet permeated our existence. It is not about an afterlife, or some divine plan or punishment. It is there IN the fabric of what we are. — Constance