4 ms·

What's wrong with the objection that, if you accept that any two universal Turing machines are equivalent in power, Searle's argument amounts to(letting P be "t

by ekiru 17y ago

What's wrong with the objection that, if you accept that any two universal Turing machines are equivalent in power, Searle's argument amounts to(letting P be "there exists an algorithm A such that any computing system executing A understand Chinese" and Q be "a human simulating a computing system executing the algorithm A understands Chinese") "Suppose P. It's obvious that ¬Q. Since P is equivalent to Q, P leads to a contradiction. Therefore ¬P"? It begs the question. Searle's thought experiment does inspire one of my own. Consider a computer that executes a sorting algorithm(mergesort, for example) on inputs consisting of sequences of number. Does it understand how to sort a sequence of numbers? What if a person uses mergesort manually to sort sequences of numbers? Does this person understand how to sort a sequence of numbers? Is there any fundamental difference between the understanding of a person who uses mergesort to sort sequences of numbers and that of a computer that uses mergesort to sort sequences of numbers?

jeffcoat 17y ago
Searle doesn't make an argument about formally equivalent Turing machines, he makes an argument about a person using an instruction book to manipulate strange characters. It's a perfect trap for your intuition. You have an intuitive feeling that if you were to have a conversation in Chinese by following mechanical instructions from a book, you still wouldn't "really understand" Chinese. All well and good, so far. But there are enormous leaps from the Searle-scenario that's so appealing to your intuition to a machine powerful enough to hold a conversation. As a trivial example, the Chinese room cannot even simulate a Turing machine unless you give the person inside rather a lot of scratch paper. You can keep countering objections like this by adding more stuff to the Room. So to hold a conversation about the weather, we'll need to add some separate input channels to observe the outside world, and to talk about the Room's plans for today, we'll need to throw in something that can keep track of time, .... it just goes on. (And while you're adding all the extra machinery, don't forget that even the original book is incalculably large, not the merely hefty tome that you're picturing in your mind's eye.) As you do this, you get farther and farther away from the original appeal to your intuition. So far that your only hope of making sense is to acknowledge that your intuitions about the simplified situation has absolutely nothing to do with a Chinese Room powerful enough to actually meet the original stipulation, that the room can "pass the Turing Test for understanding Chinese".
- dhume 17y ago
  Searle doesn't make an argument about formally equivalent Turing machines, he makes an argument about a person using an instruction book to manipulate strange characters. Right, this discussion is imcomplete without bringing in Church's thesis. * So to hold a conversation about the weather, we'll need to add some separate input channels to observe the outside world, and to talk about the Room's plans for today, we'll need to throw in something that can keep track of time, .... it just goes on.* Or these could be predefined and static. (And while you're adding all the extra machinery, don't forget that even the original book is incalculably large, not the merely hefty tome that you're picturing in your mind's eye.) This is like objecting that a Turing machine would take too many steps to solve a sufficiently large instance of some problem (e.g. more than there are Planck times in the age of the universe). The problem is still Turing-computable.
- ekiru 17y ago
  "Searle doesn't make an argument about formally equivalent Turing machines, he makes an argument about a person using an instruction book to manipulate strange characters." In what way is a hypothetical person using "a book of instructions for manipulating the symbols (the program)" different from a universal Turing machine executing the same instructions? When Turing manually executed his computer chess program, how did this differ from having a computer execute it? "It's a perfect trap for your intuition. You have an intuitive feeling that if you were to have a conversation in Chinese by following mechanical instructions from a book, you still wouldn't "really understand" Chinese." I fail to understand how this portion of what you're saying disagrees at all with what I said. I don't really see the rest of what you say as disagreeing with what I said, but it is at least not identical to it.

by ekiru 17y ago

jeffcoat 17y ago

Searle doesn't make an argument about formally equivalent Turing machines, he makes an argument about a person using an instruction book to manipulate strange characters. It's a perfect trap for your intuition. You have an intuitive feeling that if you were to have a conversation in Chinese by following mechanical instructions from a book, you still wouldn't "really understand" Chinese. All well and good, so far. But there are enormous leaps from the Searle-scenario that's so appealing to your intuition to a machine powerful enough to hold a conversation. As a trivial example, the Chinese room cannot even simulate a Turing machine unless you give the person inside rather a lot of scratch paper. You can keep countering objections like this by adding more stuff to the Room. So to hold a conversation about the weather, we'll need to add some separate input channels to observe the outside world, and to talk about the Room's plans for today, we'll need to throw in something that can keep track of time, .... it just goes on. (And while you're adding all the extra machinery, don't forget that even the original book is incalculably large, not the merely hefty tome that you're picturing in your mind's eye.) As you do this, you get farther and farther away from the original appeal to your intuition. So far that your only hope of making sense is to acknowledge that your intuitions about the simplified situation has absolutely nothing to do with a Chinese Room powerful enough to actually meet the original stipulation, that the room can "pass the Turing Test for understanding Chinese".

dhume 17y ago
Searle doesn't make an argument about formally equivalent Turing machines, he makes an argument about a person using an instruction book to manipulate strange characters. Right, this discussion is imcomplete without bringing in Church's thesis. * So to hold a conversation about the weather, we'll need to add some separate input channels to observe the outside world, and to talk about the Room's plans for today, we'll need to throw in something that can keep track of time, .... it just goes on.* Or these could be predefined and static. (And while you're adding all the extra machinery, don't forget that even the original book is incalculably large, not the merely hefty tome that you're picturing in your mind's eye.) This is like objecting that a Turing machine would take too many steps to solve a sufficiently large instance of some problem (e.g. more than there are Planck times in the age of the universe). The problem is still Turing-computable.
ekiru 17y ago
"Searle doesn't make an argument about formally equivalent Turing machines, he makes an argument about a person using an instruction book to manipulate strange characters." In what way is a hypothetical person using "a book of instructions for manipulating the symbols (the program)" different from a universal Turing machine executing the same instructions? When Turing manually executed his computer chess program, how did this differ from having a computer execute it? "It's a perfect trap for your intuition. You have an intuitive feeling that if you were to have a conversation in Chinese by following mechanical instructions from a book, you still wouldn't "really understand" Chinese." I fail to understand how this portion of what you're saying disagrees at all with what I said. I don't really see the rest of what you say as disagreeing with what I said, but it is at least not identical to it.