It feels a bit like contemporary physics has caught up to the concerns of 18/19th century philosophers.
Descartes, Leibniz, Hume, Kant and others, while disagreeing with each other in major ways, all agree on one big concern: We're fundamentally limited in our knowledge about "things in themselves" outside of our consciousness and the perceptions we receive.
Naively we think "oh, looks there's a flower!" but for these philosophers a big question was: how much can we really know about the actual thing that is the flower, beyond the (potentially suspect) information that our mind receives through the senses and our mental models (include the concept of 'flower').
In a very practical way I think we might be bumping into these limits. Which isn't surprising since what was driving these questions for those philosophers was concerns about the foundations of the then rapidly emerging scientific fields.
That isn't naive at all. Oh look, there really is a flower.
The set of sceptical propositions, say S, which make this "naive" are far more naive than the truth of there being a flower.
That era of philosophy had yet to learn that philosophical propositions are themselves subject to scepticism, and when balanced against the ordinary, are far far more doubtful.
What falls away, as naive, under scepticism is scepticism itself.
I'm not even sure what "really is a flower" even means.
Surely you'll at least agree that the concept of "flower" is a mental object that we use to classify a set of related sense perceptions.
If you're going to call skepticism "naive" then you have to at least outline what you mean by "a flower" in relation to the experience of observing one. I think you'll find the number of propositions required is not small.
> That era of philosophy had yet to learn that philosophical propositions are themselves subject to scepticism
Hume's fundamental point was that even causality cannot be meaningfully verified as real so skepticism about philosophy itself was already alive and well at that point.
Hume's starting premise is that we can only talk about ideas in our heads. Hume was wrong; outrageously so.
> that even causality cannot be meaningfully verified as real
So much for how awfully limited Hume's philosophy is. If your premises are insufficient to evidence ordinary propositions; so much for your premises. The toy model here is the deficiency, not the world.
> then you have to at least outline what you mean by "a flower"
I do not. Philosophy answers to reality, not the converse. When I pick up a flower, there is a flower. Our ability to put that into words may, or may not, be limited. The power of our philosophical cognition here is irrelevant.
That I am holding a flower invalidates all systems of philosophical propositions which assign that proposition 'False'. Scepticism does not falsify reality, rather, it is the converse.
That there are systems of propositions which succeed in accounting for the truth of ordinary such claims makes scepticism doubly absurd.
There is a world. It is the cause of my perceptions. My perceptions are caused by the world they present. I learn to perceive the structure of the world because the world has that structure. And so on.
I don't understand why you're even making this statement, no philosophical skeptic would disagree with this. Skepticism has always attacked our understanding of reality, not reality itself.
If anything it is the idealists, like Leibniz that argue that "reality is only in our minds", verging on solipsism. You seem to be misunderstanding Hume who more so points out that the only thing we can really "know" is our inner experience of reality, which is a bit closer to what you're arguing.
And the idea that there's an "inner experience" which is the object of our knowledge is the premise of idealism.
The objects of our knowledge are the world, directly.
When I open my eyes and see a flower, I see a flower. I don't see my seeing of a flower; nor do I see my inner experience of a flower --- where indeed, is the eye which sees inner experiences? And which eye sees that one?
This premise is the dogma of scepticism. Weighed against everything else it comes out vastly improbable.
When I see a flower, the object of my seeing (and my knowing) is the flower. My knowledge consists in having the experience of the flower, as caused by the flower. Without much scientific knowledge I do not know, indeed, that I am having an experience of a flower.
This talk of "having experiences" is a post-theoretical description of an event which is much more primitive. A dog which sees a flower knows there's a flower in front of it. It knows basically nothing about what kind of experience its having.
The dog succeeds in being oriented to the world as it is; the dog succeeds in knowing. As do we.
Neither of us are oriented towards ourselves. We are not peering inside our heads. Such muddles are the religion of scepticism.
Then you must have a fundamentally different qualitative experience of consciousness than I do.
The flower I am holding right now, it is real to me because I can observe myself experiencing it, however the flower you are holding I cannot experience because I am not observing your experience of observing the flower.
It is quite remarkable that you can experience that flower that I am holding and say that it's real while I cannot do the same for the flower you are holding.
> "A dog which sees a flower knows there's a flower"
I certainly don't know enough about the state of my dogs mind to know that my dog is seeing a flower, as opposed to say, merely experiencing clustered sensations in the same location as I am seeing a flower. I've looked at a flower and seen my dog eat it, so I have a suspicion that he recognizes something there, but only because my beliefs about how his actions might correlate with seeing something.
I also have friends who have seen a purple flower in the exact space I am looking where I cannot see a purple flower. What is the explanation for this?
> it is real to me because I can observe myself experiencing it
There is no such thing as "real to me". You are observing a flower. Seeing that flower means having a visual perception caused by that flower. That visual perception presents your knowledge (indeed, is) your knowledge that there is a flower.
When I look at you holding a flower I see the flower and I see you holding it. There's no mystery here. The objects of my seeing are things in the world. There is no 'private world'.
> I certainly don't know enough about the state of my dogs mind
What you 'know enough' to say is irrelevant. The proposition that the dog is seeing a flower is true regardless of what you do, or do not know. Knowledge models reality --- reality doesn't model knowledge. The proposition is true; your theory of knowledge should be revised to account for it.
> I also have friends who have seen a purple flower
The presentation of knowledge we call a visual perception, uses the mechanism of presentation we call 'my visual system' (which includes what I have learned to see). Just as a mountain is presented by different cameras, with different lenses, in different perspectives.
Insofar as I make linguistic utterances based on this presentation I'm engaged in theorising about the causal origins of my perception. Here mistakes are possible, but quite uncommon. If we think the stick is bent, we need only take it out of water to realise that the prior visual perception was caused by the refraction of light.
In this manner we learn what the causal origins of our perceptions are; and hence, rarely make mistakes.
Visual systems may be better at recognising some features of the world than others -- some cameras have zoom lenses. Likewise some may be broken. How your visual system presents your knowledge via seeing is arbitrary (water color, pastel, chalk...). Its built only to ensure that you can reliably infer its causal origin (ie., properties of the world).
But this theorising is irrevelant to what's going on. The propositions, "i know there is a flower", "there is a flower", "i am seeing a flower directly" etc. are all true. Our ability to give a linguistic account of the causal origin of this knowledge is fallible, but reality isnt.
I probably fall in the middle. We can only make statements about what's more or less probable by getting insight into what exists beyond our perception, but by definition we can't perceive what's beyond our perception so we have no data to determine which is more or less likely. Either position is one of faith, not logic. For that matter, trusting that logic is sound is itself a position of faith.
Hofstadter in GEB refers to positions like these as "axioms": statements that are impossible to formally prove within a particular system but from which we can derive statements that follow from those axioms through rules (the most fundamental of which are themselves axioms, like the statement in geometry that two points make a line) governing symbolic manipulation within a particular system. I like the concept and find it useful for wrangling logic and philosophy although I also note that it is itself subject to accepting certain axioms.
Our perception is the perception of what's beyond it -- the world is the direct cause of our experiences which present that world.
" but by definition we can't perceive what's beyond our perception "
This is one of those sceptical propositions I'm talking about. All these sceptical claims which follow "by definition" follow only by the definitions of sceptics -- definitions held (with no sense of self-awareness) with certainty.
How I would define "perception" would make such a claim incoherent or trivially false.
The light which hits a camera from a tree does not travel via some daemon. And a camera so-positioned can indeed photograph its own mechanism.
We have for at least half a century being using perception, without trouble, to perceive the mechanism of our own perception (visual cortex, retina, lenses, etc.).
All these alleged impossibilities begin from the premise that we are not within, part of, and directly causally engaged with, the world.
This is the most outrageous of all 'philosophical' propositions, the most naive, the most absurd --- and yet lies as the undoubted presumption of nearly all scepticism.
So much of knowledge in everything is just something some guy asserted in a book a few hundred years ago. Most of every field is just a guy saying "I think this because (argument based on rhetoric)", and a hundred years later we still just take that at face value. The only exception is physics, where people realized many hundred years ago that you should probably check these assertions against reality. Aristotle's claim that heavy things fall faster than light things was gospel for a thousand years, despite pretty much anyone being able to do a version of his thought experiment to conclusively disprove it, but nobody did, because it was thought you could just rationally argue your way to an accurate understanding of the world. Physics finally started pushing back against that in like the 1600s, and chemistry did a little too, though mostly by accident, but even psychology, born basically in the 20th century, was still based on whatever rhetorical arguments you put in your book, with that only changing, slowly, nowadays.
The idea that we should discount science based on rhetoric vs science based on evidence still isn't a popular one in the lay community. People hate being told that there are things they may never understand, because the human brain is just a really good monkey.
There is no evidence in rhetoric, and a more convincing argument should not be considered a more realistic one.
I am not sure philosophers have so much identified limits to our knowledge, as perhaps "thing in itself" is a vague and contentless concept that we struggle to let go of.
Descartes, Leibniz, Hume, Kant and others, while disagreeing with each other in major ways, all agree on one big concern: We're fundamentally limited in our knowledge about "things in themselves" outside of our consciousness and the perceptions we receive.
Naively we think "oh, looks there's a flower!" but for these philosophers a big question was: how much can we really know about the actual thing that is the flower, beyond the (potentially suspect) information that our mind receives through the senses and our mental models (include the concept of 'flower').
In a very practical way I think we might be bumping into these limits. Which isn't surprising since what was driving these questions for those philosophers was concerns about the foundations of the then rapidly emerging scientific fields.