Computer scientists can be a very different matter. To the degree they haven't studied biological science, they are liable to claim just about anything of their toy machines. — apokrisis

Breakthrough in Google's DeepMind:

Last night it dreamed it was a butterfly, and then awoke, wondering if it was a butterfly dreaming.

EDIT:

Should substitute cat for butterfly, and videotaping for dreaming.

Are there any cognitive neuroscientists or psychologists who could be direct realists? The only one that springs to mind is James Gibson. — apokrisis

That has to be taken with a grain of salt, because it depends on how familiar a scientist is with the philosophical arguments. Sometimes a scientist will publicly articulate a philosophical position that's not terribly sophisticated, but they act as if the science backs it, because they don't know the depth of the philosophical discussion on the matter.

Accuracy is reimagined as successful adaptation. Truths are word-tools that work. What is it to work? There we move into the realm of feeling and ineffability. — t0m

That's interesting. But that it can't answer why the word-tools work means that philosophical questions remain. Maybe Witty relegated that to the mystical. I understand the appeal of that.

Let's take the example of minds, dreams, perceptions. On a pragmatic account, they do a pretty good job of determining truths like whether the tree is a threat to my house. But they leave open the question of whether my experience of the world is all there is.

I think they naturally occur. But then a sophisticated tradition emerges. Would you agree that metaphysics can become a clever game? — t0m

Yeah, sure.

If I may rewind: let's say your OP is 'really' about what is good or virtuous. — t0m

It's not. I just mentioned the Cyrenaics as an example of people who acted on their metaphysical conclusions.

It's more similar to mathematical questions such as whether P=NP or not.

If we can't be reasonably sure that our perceptions are of external objects, then we have nothing to base our empirical knowledge on. And we have no justification for other minds.

Then metaphysicians rip these tools out of context and try to do eternal super-science with them... — t0m

Did these questions originate with metaphysicians, or are they ones that naturally occur to human beings upon reflection?

So are you a data stream within a data stream?

Both Marchesk and creative soul are data streams in my brain, as is the sensation from my fingers as I type. — charleton

Is your brain also a data stream?

There are pragmatic differences between those situations that are easy to characterise. — andrewk

The pragmatic differences is what led to the philosophical questions. We can all be pragmatic and ignore philosophy if we want. But some of us don't want to.

What does it mean to say that "we behold a mental construct"? — t0m

It means that perception is experienced inside our minds, just like the case with dreams.

How is this "cashed out" in action? If we somehow knew that is was true, then how would we behave differently?

Well, there was a philosophical school in Ancient Greece called the Cyrenaics who built up an entire way of life based on following through with perception being mental. If we don't have access to external objects, then only our bodily sensations matter, and thus, pleasure is the only good.

I'm suggesting that we trace fuzzy distinctions back to the practical concern that employs them. (In short: pragmatism.) — t0m

But metaphysical questions aren't concerned with being pragmatic. If you want to be pragmatic, then everyday common sense and science are enough. But some human beings like to ask questions about the nature of our existence, what we can know, etc.

That's a really good answer, Apo. But direct realists would make an exception for veridical perception and say that it's one way information flow from the senses to the brain. That's what makes it veridical (that and the causal history from light bouncing off tree into eyes).

The reason the language game answer doesn't work for this is because the difference between a dream tree and a perceived tree matters a great deal. If I dream of a tree falling on my house, but upon wakening, realize there is no tree near the house, then I forget about it.

But if perceive a tree looking like it might fall on my house, then I will take action. Similar with hallucinations. If I hallucinate an intruder in my house, then I'm not in any danger. But if I perceive one, then it's time to call the police.

What this points out is that there is a fundamental difference between experiences. Some of them are mental. They are generated only by my mind. And some are public. The police can show up and find evidence of an intruder. Other people can perceive the same things I do.

Public experience is objective, and that allows us to do science, to agree on language games, and so on. There is a reason that we developed objective methods for inquiry. And there's a reason science disregards subjective experience. My dream of being abducted is not evidence for the existence of aliens.

So when philosophers debate whether we have direct access to public objects, they're concerned about issues like skepticism. If there is a veil of perception between us and the world, then how doe we know it's there? Maybe other people are just dream people, etc.

If you really do exist as a 'experience-orb' there's just no way of knowing if there really is a tree (or more importantly, other orbs) out there beyond your experience. — antinatalautist

Well, what happens when a tree falls on you and no other orbs are around to experience it? Does your experience end? Let's say you didn't even notice the tree. It's not real to you or anyone else. Do you still die?

That's the problem with idealism. It's absurd, because it creates a gappy world between experience that still somehow affects who gets to experience what. So some other experience orb will find your squished body and realize a tree fell on you. If nobody experienced the tree, then why did your experience orb come to an end?

I stated that without the concept or idea of what a tree is, there is/may be no tree. — Cavacava

Okay, but then what happens when you decide to run through the unconceptualized blob of green & brown?

So, when looking at a tree, are you aware of the tree or your mental representation of it. — Harry Hindu

I'm aware of the tree.

It's like asking, "Are you aware of the word, or what the word refers to?" They are both separate things that are linked together by representation. Because it is a representation, you could say that by being aware of one as a representation, then you are aware of what it represents. — Harry Hindu

But then what does a dream tree represent?

Ah, the infamous duck-rabbit. Banno would be proud. It's interesting, but the thing is if you had never heard of a rabbit before, and you saw one, you wouldn't confuse it for a duck. You would just think it was some cute, furry mammal with big ears that hops around, and then ask people what it was.

This is because whether something is mental or not depends on context. — Magnus Anderson

The worry is that if see a mental image while perceiving a tree, then how do we know there is a tree at all? It could be just like a dream tree. That naturally lends itself to skepticism, where the context is undermined by holding all of perception in doubt.

So is perception of a tree... phenomenological given and therefore we play a passive role or is the tree a representation which we actively construct, and are responsible for? — Cavacava

I don't have much control over seeing a tree. Maybe some drugs and meditative exercises would help me see it in some other manner?

I would say perception is given.

How do you square it? — apokrisis

Pun intended?

I agree that this is an attractive position to take, But it is fundamentally inconsistent. — apokrisis

The reason is because color is likely creature dependent, while shape is not. Shape is objective, and doesn't depend on the kind of eyes we have.

But you're wondering how perception can involve awareness of both mental and non-mental properties of an object. That is a good question.

ut I've yet to see anything that suggests there is any difference between 'being conscious of a mental tree' and 'being conscious of a tree itself', beyond the differences in the strings of letters that make up the two phrases. — andrewk

So you see no difference in meaning between dreaming of a tree, remembering a tree, visualizing a tree, hallucinating a tree, and perceiving a tree?

Fine. Answer that version of the same question then. — apokrisis

I don't know. What makes perception qualitatively different from other mental experiences? It is remarkable how much a dream seems like you're perceiving. The disjunctivists deny that the experiences are the same. I'm not sold on that.

When you perceive this actual tree, is it’s greenness also actual? Or mental? Or what? — apokrisis

I side with mental on color, but not shape.

Simply seeing a tree with your own eyes is not enough for the tree to be considered non-mental. What if you're inside some sort of virtual reality, for example? You need context. — Magnus Anderson

We're in our world, regardless of what the actual metaphysics are. Does the act of perceiving a tree make us aware of the same sort of thing as it would while dreaming, hallucinating, visualizing?

That one made me laugh. Show me the simple definition of direct realism, or even indirect realism, in this SEP entry - https://plato.stanford.edu/entries/perception-episprob/ — apokrisis

It is simply stated as whether there is mental mediary we're aware of when perceiving an object. If no, then direct realism is the case.

The arguments for or against direct realism is where you get the "100 shades of gray". But the issue is stated simply, until everyone and their grandma goes off on tangents around the meaning of terms like direct, access, and realism. The semantic dispute over terms then gets conjoined with the arguments for and against the question of whether we behold a mental construct, or the thing itself.

So I ask you again, do we or do we not behold a mental construct of a tree when we see a tree? I honestly don't care which way you answer, since I'm not sure myself. But I do care about the argument being able to proceed without semantic muddle.

How can it be illegitimate to talk about the tree perceived in a dream? — apokrisis

Because perception doesn't occur in dreams. If you want to attack direct realism with dreams, then you need to say the experience is the same, That's the reason the argument from hallucination has bite.

These are deep philosophical issues, and not merely language games, for a reason. — apokrisis

I agree, but it never helps in these discussions when the result is endless semantic dispute because nobody ever agrees on how the terms should be used.

It's weird, because I can go to SEP and it will clearly state what direct realism is about, but then I come here, and it's muddled semantic confusion the entire time.

And I understand that not everyone will agree with a philosophical position. That's fine. But when we can't even agree on what terms mean, then the debate just meanders all over the place with people talking past one another. And i'm speaking in general here. We've had 100 page long disputes over apples and cats on mats in the old forum which went the same way.

There was one thread which ended with antirealism being associated with direct access, whatever that could mean. Basically, a melding of Wittgenstein and direct realism.

So good luck with your ambition making things really, really simple. These are deep philosophical issues, and not merely language games, for a reason. — apokrisis

I didn't come up with the direct/indirect realism debate.

Are we talking about a dream tree? — apokrisis

No, we're talking about the perceived tree. Is it a mental image or not? That's what direct/indirect realism comes down to. All this other stuff is confusing the issue.

Are you Marchesk or are you referencing something other than yourself by virtue of using "Marchesk"? — creativesoul

Charleston's referencing of Marchesk is ideal*, but I'm real. I'm physically identical to myself, although not the label.

* or perhaps not, shouldn't flatter myself

What feature (or physical property) of a computer is analogous to physiological sensory perception? — creativesoul

There isn't. The equivalence would be functional. Someone could probably a hook a camera up to a physical artificial neural network, where the neurons are somehow realized physically, instead of just being software functions. But it still wouldn't be biological.

Ok. I had always worked under the assumption that all binary code consists of true 'statements'. You're denying that? Right? — creativesoul

Yeah, the binary code can be any statement that can be represented by 1s and 0s.

So maybe the statement would be (in human terms):

"There is a 94.57% probability there is a cat in this Youtube video."

Which represents the confidence the network has in making the classification, I think.

Here's a link to simple neural network tutorial using Python that explains the basics, if you're curious about how actual code works (for simple examples):

https://medium.com/technology-invention-and-more/how-to-build-a-simple-neural-network-in-9-lines-of-python-code-cc8f23647ca1

I was just showing that code can be false, and that was pseudocode, but I updated with real code from a programming language.

It doesn't have anything to do with neural networks, just that you can represent false statements in code, and I'm using the unicode character for a cat face, because some programming languages let you use any unicode character.

Although maybe you meant the code has to be true in the error free sense, although errors can crop up while the code is running, of course.

I'm not knowledgable enough regarding how computers work to say much at all regarding that. However, it is my understanding that binary code still underwrites it all. Is that correct? — creativesoul

It's all binary in that the circuit logic is based on boolean algebra (true/false or 1/0). The instructions a processor carries out are based on combinations of 1s and 0s. But the functionality humans care about is understood at an algorithmic level, because that's what we designed computers to do.

A trained neural network that recognizes a word would have a vector of positive and negative real numbers representing that word. But nobody really understands what those numbers represent. They're the outcome of training a network to recognize the word "cat" for example (written or auditory depending on the network). They're the different weights and biases of the inputs that make the network recognize "cat".

Of course those real numbers are stored as bit patterns.

As a stand in for all sorts of things from rudimentary seeing and hearing to complex linguistic conceptions... — creativesoul

A perception shouldn't be a synonym for a conception, so there needs to be some differentiating there. And a "cat watching" neural network is only classifying different pixel patterns that match up to what humans recognize as cats with a certain degree of accuracy.

Pay very close attention to how the term "perception" is being used in these discussions. — creativesoul

That's a good point. How do philosophers typically define perception?

see "that cat there", a judgement grounded in the matching development of a generalised capacity for categorising the world in terms of the long-run concept of "a cat". — creativesoul

The pigeon doesn't understand "the cat" as a cuddly pet or abstract concept, but it can still recognize it, and likely has a similar visual experience to humans.

If your argument is that the brain has the goal of being "as direct and veridical and uninterpreted as possible", then that is the view I'm rejecting. It is a very poor way to understand the neuroscientific logic at work. — apokrisis

Let's make this really, really simple. What is the result of visually perceiving a tree?

A. Seeing a mental image.

B. Seeing the tree.

I'll let your unsupervised neural network categorize the two.

No neuroscientist could accept that simple account. Neurons respond to significant differences in the patterns of connectivity they are feeling. And that can involve thousands of feedback, usually inhibitory, connections from processing levels further up the hierarchy. — apokrisis

And no computer scientist is going to say that all an algorithm is doing is reading a magnetic charge.

I can see why you might then protest that the shapes of objects are just self-evident - unprocessed, unvarnished, direct response to what is "out there". — apokrisis

The brain has to do be able to recognize a shape somehow. It's not magic, and shapes don't float along on photons into the eyes and travel from there on electrons into the homunculus sitting in the visual cortex.

A distinction needs to be made between naive realism, where unreflective and unscientific view of seeing the world is like looking out a window onto things. Obviously, that's not how it works. No philosopher is going to defend a totally naive view of vision which involves an object showing up in the mind magically. There has to be a process.

The question is whether the process of perception creates an intermediary which we are aware of when perceiving, or whether it's merely the mechanics of seeing, hearing, touching, etc.

The computer simply responds to the magnetic charge on the hard drive. — Michael

And if the algorithm in question is using thousands of GPUs or TPUs (tensor processing units) reading from a bunch of solid state drives over a server farm, or being fed data over a network?

You could argue that a neuron simply responds to an electrical charge from a connected neuron. What does that have to do with perception?