Comment by danielam | Hacker News Reader

Comment by danielam | Hacker News Reader

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I thought the beginning of the interview showed promise, but toward the end the conversation unmoors from the topic at hand.

I really do wonder how many in the field of AI take as philosophically unsophisticated of an idea like intelligent computers seriously and see it as an obvious and uncontroversial possibility. What Hofstadter is dancing around is that intelligence requires semantics and semantics is exactly what computers, by definition, lack. Knowledge is semantic in nature and thus computers cannot, strictly speaking, know anything. They cannot reason because, again, reason requires semantics. Now, we are able to model and then formalize some domains of reality under some aspect well enough such that computers can behave in very useful ways, but no matter how sophisticated such programming gets, it cannot somehow magically cross over into semantics. The notion is patently absurd. So to say that AI is, literally, far from being intelligent is like saying the color red is far from being a strawberry. No amount of red will ever amount to a strawberry.

P.S. I was reminded of this post about Sphex wasps and intelligence, with mention of Dennett and Hofstadter: http://edwardfeser.blogspot.com/2013/12/da-ya-think-im-sphex...

Knowledge is semantic in nature and thus computers cannot, strictly speaking, know anything.

And a group of biological neurons can?

They can by virtue of being embodied. It's the body interacting with an environment that provides semantics. For humans, a lot of that is cultural. Computers only have knowledge to the extent that we deem those patterns of 0s and 1s to be information.

Not clear to me what you mean.

I can agree that knowledge ultimately is grounded in sense experience ("the body"). Thus, the knowledge of "Horse" (or "Horseness") must ultimately be traced to sense experience involving particular horses.

I can agree that the "bits" in a computer (strictly speaking, not bits but physical states under that interpretation) are only meaningful by convention and not intrinsically. Thus, we say in one context that states labeled 11100 represent the integer 28 and a sequence of five Boolean values in another context, depending on the conventions of each context.

I can agree that conventional meanings are often cultural like commonly understood meanings of the symbolic which, again, lack that particular meaning intrinsically. E.g., both nodding and the utterance "yes" are generally meant to express agreement (except in countries like Bulgaria).

However, I do not understand what is being said when invoking embodiment and culture in this context, specifically.

Eh, your idea of embodiment is iffy. Computers can interact with an environment. Eventually computers will be far more able than humans to interact with environments. Humans are equipped with a very advanced set of input devices we call senses, but after that point we have to use technology to translate what we cannot perceive into information we can. You cannot see ultraviolet, you have to translate it into visual light, which is then translated into neural signals. A computer system directly, or indirectly connect with just about any sensor we can think of and directly manipulate that signal.

I don't know what goatlover meant, and I don't presume you are necessarily arguing this point, but adding sensors to computers does not overcome the fundamental nature of computers I described above.

That's a really interesting point. I never thought about knowledge like that.

I've always thought that the difference between knowledge (or knowing something) and being informed is when you can apply information gained in one realm to another.

So you're saying we need a robot?

Can they?

"intelligence requires semantics and semantics is exactly what computers, by definition, lack"

This sort of assertion is experimentally untestable, not rigorously derivable from any axioms that people agree on, has no predictive power, and amounts to vague opinion passed off as fact. About a hundred years ago you might as well have been arguing about how "philosophically unsophisticated an idea like flying machines" was because flying is, strictly speaking, a behavior of flying animals.

Please explain how to tell if some being "has semantics". Suppose we encounter some alien made out of crystal and metal, but arranged in organic looking structures. We work out how to communicate, rather roughly (like Google Translate). They won't talk about their ancestors so we don't know if they were built or evolved.

How do we find out if they have semantics?

Computers aren't a black box mystery. We understand how they work. We understand that they are implementations of Turing machines (or similar computational models), and Turing machines are by definition a formalism and thus syntactic in nature. Computers are therefore no more than syntactic machines (I would further claim that computers aren't strictly speaking syntactic machines either, but physical artifacts -- and we can use different physical properties and states toward this end -- that simulate a formalized, syntactical system). Syntax as such is semantically blind, so to speak. Human beings, on the other hand, do "possess" meanings. We have concepts. Pure syntax can never amount to a single concept anymore than purely speaking about climbing Mt. Everest ever itself amounts to actually climbing Mt. Everest. Any semantics we associate with computer programs is entirely an act of interpretation on the human end.

You have not established that being a syntactic machine rules out semantics. The use of phrases like 'no more than' and 'purely' do not make the case; instead, their validity here is dependent on the premise.

> semantics is exactly what computers, by definition, lack

What do you think the definition of a computer is?

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