HN user

curious_yogurt

37 karma
Posts0
Comments14
View on HN
No posts found.

The claim seems accurate to me, at least for Scheme: that is, lambda calculus does underlie Scheme.

Lambda calculus, as articulated in Church's 1935 paper, gives us a way to understand computability. But if we look specifically at Operation II in the paper (p. 347), what we have is the lambda function in Scheme. Given that every function in Scheme (including special forms) is equivalent to some lambda function, it seems that in virtue of Operation II we can say that lambda calculus underlies Scheme.

Whether we can push this further to say that lambda calculus underlies McCarthy's initial conception of LISP, or some arbitrary version of Common Lisp, I do not know for certain. But if all these versions treat lambda functions the same way as Scheme does (in relevant respects), then the claim holds for Lisp generally.

[1]: Church. An Unsolvable Problem of Elementary Number Theory. _American Journal of Mathematics_, Vol. 58, No. 2. (Apr., 1936), pp. 345-363.

To be fair, I did not ask the question of whether "the room understands." The question was whether "the person in the room understands," which seems perfectly reasonable.

In order to grasp what you are saying about "Microsoft the company understand French" one needs to define what we mean by "understand." As you (correctly) say, our answer will depend on that definition.

But to say everything depends on our definition of understanding is to miss the point of the Chinese Room. The point of the argument is to support the claim that the sort of thing we normally classify as understanding—such as when we say someone understands Chinese—is not a property of the person following a lookup table (or by analogy, a machine with instructions). Thus, neither the person in the room, nor the machine, understands in the same sense as when we say "this person understands Chinese."

This is how the Chinese Room is supposed to work against Strong AI. Strong AI supposes that when you have appropriate instructions, a machine is said to understand in the same sense in which you say a human understands. The Chinese Room argument is meant to prompt the claim that the machine does not understand—or at the very least does not understand in the same sense that a human understands.

I think you have put your finger on exactly what is at issue: it does not matter whether the program is pencil or paper or electronically. It's an analogy. The point is that we do not (says Searle) impute understanding to the person in the room, therefore we should not impute understanding to a computer running a program. But Strong AI requires us to impute understanding; and this is exactly what is impossible. Therefore Strong AI does not exist. I take that to be the force of the argument.

I do not believe I have presupposed the answer; I have simply articulated how I believe the reductio to work.

The key, of course, is whether we think that the person in the Room actually understands Chinese. The inference Searle wants us to draw, based on our intuition, is that the person does not understand Chinese just because the person is following a lookup table. The way to get around the argument is to claim either (i) that the inference doesn't work—that is, Strong AI does not imply machines understand, or (ii) that the Chinese Room does not imply machines do not understand.

I think (i) is a reasonable claim that follows from understanding what is intended by the term "Strong AI." (ii) is the tricky one. It seems to me the best route out is to find a way to substantiate a claim alluded to by another commentator, viz. the property of intelligence does not exist (though I would say "understanding does not apply" or something like that). The thing is, it does seem to me that understanding is a reasonable category for this case; and anyone who thinks this is likely to feel the force of the argument.

The Chinese Room is a reductio against Strong AI. Strong AI is the idea that a program that programme that is able, for example, to converse in Chinese thereby understands Chinese. The Room, if successful, drives a wedge between "acting as if one knows Chinese" and "understanding Chinese". This may be applied to the any number of programs. But with such a wedge, we do not actually have Strong AI—the appearance of intelligence (grounded in syntax) is different from actual intelligence (presumably grounded in semantics).

In other words, assume strong AI. Strong AI implies machines have understanding. But the Chinese Room argues machines can never have understanding. So, strong AI is not possible.

In the background is Turing's attempt to provide an account of intelligence. Turing skirts the issue in his famous paper "Computing Machinery and Intelligence"[1]: instead of defining intelligence, Turing proposes a test. But the Chinese Room argues that even if we had a machine pass this test, we would not thereby be bound to say that the machine was intelligent.

[1] https://www.csee.umbc.edu/courses/471/papers/turing.pdf

It seems to me that the argument is not meant to address the value judgements of people doing work in applied ML.

The basic idea of the Chinese Room is that the Turing Test is inadequate—such that even if a machine could pass the test, we would not be permitted to infer that such a machine is intelligent. This is significant for the distinction between syntax and semantics, as well as any mechanical account of mind that integrates the results of computational logic. And indeed it does seem like many people do wonder about the nature of machine intelligence and about whether we can give a coherent account of the mind from a mechanical perspective. So perhaps some people doing work in applied ML do not care about these questions; but it does not follow from this that such questions are without qualification uninteresting or worthy of being considered.

I think it is a rather bizarre suggestion that one should read Plato in the order believed correct in antiquity. For one, it seems to me that the ancients were incorrect about that order. And, as you say, there are several dialogues the authenticity of which are in doubt and so should probably not be read before other (usually more central) dialogues the authenticity of which are not in question.

In terms of order, you can do worse than begin the five traditional "death of Socrates" dialogues. These are the Apology (Socrates' trial speech and the nature of the philosophical life), the Crito (the nature of law and implicit political contracts with the state), the Euthyphro (the nature of piety), the Meno (the nature of virtue and knowledge), and the Phaedo (the afterlife and universal objects).

These five dialogues are from different periods in Plato's writing: the Apology is probably quite early and is a good introduction to Socrates; the Euthyphro is a nice "what is x?" dialogue which comes to no resolution, which is typical of early one-on-one exchanges, and although fictional might be the sort of thing the actual Socrates went around doing; the Crito is probably a late-early dialogue, and mixes in some more serious concerns about the nature of the state that will capture Plato's attention in his later writings; the Meno starts out as a "what is x?" dialogue, but the second half transitions to consider the nature of knowledge and how we can know anything (if at all); and the Phaedo is a full-blown middle-period dialogue where Plato deploys his account of universals called the Theory of Forms (which he arguably discards or submerges in the late period, but is generally what people think of when they think of Platonic doctrine).

After the Phaedo, I would hit the other big middle-period dialogues that are classic Plato: the Republic, the Symposium, the Phaedrus. The Republic may very well be the greatest piece of philosophy ever written; if not, it is up there in the top five-to-ten. It ostensibly deals with the nature of justice, but it covers huge areas including knowledge, beauty, truth, education, and more. It develops some of the themes from the Phaedo. The Symposium is a collection of beautiful speeches on the nature of love, again developing some of the themes of the Phaedo, but also the Republic. The Phaedrus looks at the nature of love and the nature of rhetoric, picking up themes from the Republic and the Symposium.

That's a lot of stuff. If you want one and only one thing to read that's short, go for the Apology. If you want one and only one thing to read that's all-encompassing, go for the Republic.

The idea that Plato was "impressive for his time," but with the inference that he is not now, is something certainly held by some modern-day philosophers. But it is not a generally accepted view. The reason is that philosophy is (for the most part) not a subject that sheds its skin — whereby the "old sources" are discarded in favour of the new, generally speaking.

I say "generally speaking," because there are parts of philosophy like this; in particular logic, where the development of formalization in predicate logic, in the nineteenth and twentieth century eclipsed the categorical formalizations of Aristotle and the propositional formalizations of the Stoics. But Plato's argument against instantiated universals in the 5th century crops up when anyone wants to do serious work on universals—and this holds up to the present day. Or, for example, anyone serious about the notion of knowledge would do well to carefully examine many of the arguments in the Theaetetus to discover where the blind allies are when it comes to giving a rigorous definition of knowledge.

Of course, knowing Plato will help you with historical context. But that historical context reaches across the centuries and informs present day conversations in philosophy. The reason is that philosophy is a particular practice and way of approaching the world, rather than a body of doctrine. In turns out that the way Plato approaches a particular problem will shed light and spur new ideas about how to approach that problem—such that we can juxtapose, say, Plato's conception of universals with D. M. Armstrong's conception of the same. Or Plato's conception of knowledge with that of Bacon or Karl Popper.

So, I take issue with the claim that there are "far better things to be reading now." There are many great things to be reading now; but that does mean that Plato's work has been eclipsed, or that we have nothing to learn from reading his work beyond satisfying historical curiosity.

It seems to me that the claim that Plato's "actual argumentation is generally pretty bad" is something that might be challenging to defend. It is a very sweeping claim, and it also assumes the argumentation of the author is reflected by the characters in the dialogues. Even if we were to weaken this to say that the actual argumentation of the characters in the dialogues is generally pretty bad, I think that it would be challenging to defend this claim. I'm not saying it's not possible; but it would be interesting to see if it could be sustained. My guess is that it would not be possible to sustain such a general claim.

Bertrand Russell, of course, is a master of logic. But if you are drawing from his History of Philosophy, I'm not sure that is a particularly good source for views on ancient philosophy. I tend to think the best way to justify a claim is to look at the primary sources themselves (if we have them—which in the case of Plato we are pretty sure we have everything he wrote and then some extras).

In terms of scratching the surface, much of what Plato contributes is ways to approach particular problems. For example, if you look at the treatment of universals in the Parmenides and the Philebus, the approaches in the arguments here (severally considered) have a lot of staying power: in particular, you find related arguments being made regarding universals by Aristotle and on, going all the way up to the present day (including, for example, Bertrand Russell). What is going on here is not merely philosophical scepticism (though there is that), but also approaching and techniques that need to be solved in order to make progress on a particular problem. So, that is an example of how the dialogues go beyond simple scepticism. There are so many other examples: the dialogues are packed with them — which is part of the reason why treatments of many modern philosophical problems and approaches can be traced back to Plato.

Does Plato actually advocate this? If you are referring to an argument Socrates makes in the Republic regarding politically motivated lying, it seems to me not unreasonable at an initial glance to say that Socrates represents Plato's position.

But it also seems to me that there are other ways to take this. First, the Socrates in the Republic is a character in an exchange — and so it seems not unreasonable to think that perhaps that character is not a simple mouthpiece of the author. For example, nobody would say Hamlet is Shakespeare's mouthpiece. Second, there are dialogues where Socrates gets completely trounced by his opponent — in particular, the Parmenides. Interpretations of what is going on in the Parmenides are diverse; but at the very least it seems that Socrates is not Plato's mouthpiece. Third, if (contrary to the previous two points) it turns out that Socrates is Plato's mouthpiece, but that mouthpiece is telling us that Plato will manipulate the reader as he sees fit, then it seems at least possible that the whole idea that Socrates is Plato's mouthpiece is itself not a straightforward claim. Thus, the grounds for your claim that one should be careful about applying this principle to Plato — assuming I am right that you base it on evidence in the dialogues — is not entirely solid.

As an additional point, it seems to me that even if the author wants to manipulate the reader, it still stands us in good stead to have a principle of charity. It is a starting point, not an ending point.

Indeed, questioning assumptions is a part of what hopefully comes out of a careful reading of Plato's dialogues. But it is much more than this. Plato not only tries to figure out which questions are worth asking, but embeds a plethora of different approaches and ideas in his dialogues. Many of these approaches and ideas are specific to the type of question under discussion—part of why we have different classes of arguments for different topics.

I do agree with you that you should not expect to uncover some magical idea in Plato's works. But this is certainly not what Plato intended us to do. Instead, what Plato is trying to do is encode philosophical practice. This entails not a collection of ideas (magical or not), but rather an approach to philosophical discourse and hence to the world. Curiosity and scepticism, as you correctly point out, are important and are recurrent themes. But this just scratches the surface.

So if Plato is misunderstood, it is because he failed to make himself clear by clearly stating that an easy way of misunderstanding him is not what he actually meant.

I think your inference is partly true, but partly not true. In some cases, of course it is the case that by not saying "this is an easy way of misunderstanding" a particular claim does lead to Plato being misunderstood. But Plato is very much unlike Aristotle or the vast majority of other philosophers in that he wrote dialogues. These dialogues are (almost entirely) fictional, but they read more like a play than a treatise. So, it's not always the case that Plato is trying to be clearly understood in terms of propositions being conveyed in language.

For example, in the dialogue the Phaedo, Socrates is talking to two Pythagoreans about life and death. They ask Socrates to make arguments supporting their quasi-religious beliefs that the soul goes on after death, which Socrates does. But he does so in a very interesting way: the sequence of arguments keep pushing them until they become uncertain about their beliefs concerned the afterlife (which they then express).

So the question is: what does Plato actually want us to take away from this sequence of arguments? It seems, at least, that he is not coming at it head-on. He is not saying you should believe proposition P. Hence my scepticism that you claim is wholly true — that Plato is misunderstood because he failed to make himself clear. I do not think it is obvious that being clear was always Plato's ultimate goal. My suspicions are that he wanted to put the readers into a position where we have to figure out what we actually think is true, and what we think about the arguments themselves. I guess what I want to say here is that making himself clear, in the sense of stating propositions, is not obviously the goal of Plato.

This is not starting off well. The first rule is to interpret him in the most favorable way possible

Actually, as a principle of reading in general, this is not a bad one. It does not mean that we have to decide that the most favourable interpretation is the one correct interpretation, but it does mean that it is reasonable to search for such an interpretation in the beginning. This is called the principle of charity. The reason the author recommends it is that often people will impute a particular view to a philosopher that implies the philosopher made elementary errors in reasoning or obvious falsehoods.

This may, of course, be the case. It is trivially true that philosophers make invalid or weak inferences, and false claims.

But there are two good reasons to adhere to the principle of charity that the author does not make explicit. First, if we do not, then we often end up short-circuiting our understanding of what the philosopher may be trying to say. That is, we may prematurely dismiss the claim as absurd instead of trying to sort out what might be the actual claim. Second, while part of philosophy depends on what philosophers are actually saying, a good part of doing philosophy is figuring out what our response to a particular claim is, how we ourselves would support that claim (if the inference is invalid), and what claim we would put in its place (if the claim is false). If we do little more than dismiss a claim as absurd, then we are not really doing philosophy.

So I guess what I am saying here is that making the assumption "Plato is a smart guy" is actually not a bad start for one taking a serious study of what he has to say.

[1] https://en.wikipedia.org/wiki/Principle_of_charity

Critical thinking books vary widely in quality. They often get bogged down in long catalogues of fallacies and categorical logic (which, while interesting, is not as useful as sentential logic and some elementary strategies in first-order logic).

One of the shortest, simplest, and most reasonable books I have encountered is "A Rulebook for Arguments" by Anthony Weston, now in its fifth edition.[1] It's about 118 pages long, and is broken up into two basic sections: the first deals with general argument-rules, and then looks at some common sorts of inductive arguments in detail, as well as some common deductive argument-forms; the second deals with how to develop an extended argument, as well as how to compose argumentative essays and oral arguments. An appendix has brief treatments of some common fallacies.

The Rulebook does not have exercises, which some might find useful. But it is brief and to the point, written for the learner in mind, and its presentation is supported by strong examples. The advice for composing and presenting arguments tilts to the academic side of things, but is still generally applicable. The point of this book is to start you down the path of not merely appearing to be a competent reasoner, but to help you increase your analytical ability, and then to persuade others by means of stepping through a carefully reasoned argument.

[1] https://www.hackettpublishing.com/a-rulebook-for-arguments-4...