Philosophy of Computer Science: Online Resources

Position Paper #5:

Can Computers Think?

Assignment

A Debate

Pro: If something behaves in all relevant ways as if it were cognitive, then it is cognitive.

Con: What do you mean by "being cognitive"?

Pro: I mean that it can perceive (see, hear, etc.); has beliefs, desires, and intentions; can remember; can use and understand natural language; and can reason and make rational decisions; etc. You know, the sort of thing that AI researchers are trying to achieve by computational means.

Con: Do you think they will succeed?

Pro: I'm optimistic: I think that a computer running a suitable AI program (or maybe a suite of programs) will eventually behave in all these ways.

Con: But that means that you think that such an AI-programmed computer will be cognitive?

Pro: Yes.

Con: But that's crazy! Computers and computer programs are purely syntactic!

Pro: Now it's my turn to ask for clarification: What do you mean by 'syntactic'?

Con: I mean that all a computer can do is to manipulate the symbols of a formal symbol system (see §13.2.2 of the book).

Pro: So what's the problem?

Con: The problem is that cognition is semantic! That is, it involves the semantic interpretation of those symbols.

Pro: Well, I'm not so sure about that. But suppose you're right. What then?

Con: Well, syntax does not suffice for semantics. So, no computer executing a purely syntactic computer program can exhibit semantic cognition, even if it behaves in all relevant ways as if it were cognitive.

Argument Analysis

• Try to rewrite Pro's and Con's arguments in terms of premises and conclusions, and then analyze and evaluate those arguments. That is, "extract" each argument from the debate and put them in the following forms:

  1. Pro's premise 1		1. Con's premise 1
  2. Pro's premise 2		2. Con's premise 2
  (etc.)		(etc.)
  Therefore, Pro's conclusion		Therefore, Con's conclusion

  Then evaluate each argument.

• Keep in mind that premises and conclusions are declarative propositions (they can be deemed to be true or false) but that some lines uttered by Pro and Con are not declarative propositions (and thus can't be premises or conclusions). For example, Con's first statement is a question—it is not a premise or conclusion of anyone's argument—and Pro's second statment needs to be reformulated as something like "Something is cognitive means that it …".

Ground Rules

1. For your peer-editing session next week, I will give you a choice: You may either:
   1. Create a "thinksheet" like the one for Position Paper #4
      • with one column listing the premises, conclusions, and arguments;
      • one column of "cells" to indicate your agreement or disagreement with them;
      • and one column of "cells" to indicate your reasons for your agreement or disagreement

   2. or write a 1–2 page, double-spaced (that is, about 250–500 word), single-sided, first draft.

   (Of course, you might want to do option (a) for your own use before doing option (b)! They are not mutually inconsistent.)

   If your document is more than 1 page long, please staple the pages together and make sure that your name is on all pages!

2. Please bring 5 copies to class on the due date.

3. At the top of the first page, please put the following information:
   1. the title "Position Paper #5"
   2. your name
   3. the course you are enrolled in
   4. the due date.

4. Failure to correctly distinguish among "true (or false) sentences, propositions, statements, premises, or conclusions" and "valid (or invalid) arguments" will also result in a lower grade!

   To the Instructor: I have found that many students have trouble distinguishing among these terms, hence my insistence on their importance in this position paper.

5. For general assistance with writing (including a suggested method of paper preparation and format, as well as advice on grammar), see my website "How to Write"

   And don't forget to give full citations to any sources that you cite.

Suggestions and Guidelines for Peer-Group Editing

1. When you get into your small groups, introduce yourselves quickly, and share copies of your papers with each other.

2. Choose one paper to discuss first.
   (Suggestion: Go in alphabetical order by family name.)

3. After spending about 10–15 minutes on the first paper, move on to the next, going back to step 2, above, changing roles. Spend no more than 15 minutes per paper (because you've only got about 45 minutes at most). Perhaps one member of the group can be a timekeeper.

4. Suggestion: There are really 2 arguments in this dialogue: Pro's argument and Con's argument.

   So, the first task is to present each argument. Once you have identified the premises (including any hidden premises) and conclusion of each argument, you can then analyze it for validity of the argument and truth of the premises.

5. For each paper in your peer-editing group, ask as many of the following questions as you have time for:
   1. Did the author present both Pro's and Con's arguments?

   2. For each argument, did the author state whether and why they believe the argument to be valid?
      • It's possible to formulate both arguments so that they are valid!

      • If you do that, then ascertaining the truth value of the premises becomes your central task.

   3. For each argument, did the author state whether and why they agree with the premises?

   4. For each argument, if the author believed either that the argument was invalid (even with missing premises added—that is, that there was no way to make the argument valid) or that one or more of the premises was false, then did the author state whether and why they agree with the conclusion?
      • Reminder:
        1. If you think an argument is sound, then you are logically obligated to believe its conclusion (and you don't have to give any other justification for the conclusion).

        2. If you don't believe the conclusion of an argument, then it is either invalid or else has at least one false premise; you must identify which, and explain why.

        3. If you think an argument is unsound (either because it is invalid or has at least one false premise), then you might still believe the conclusion for other reasons; in that case, you must give those other reasons.

6. Remember: Your revised paper must have the appropriate heading at the top of the first page, must use the terms 'true', 'false', 'valid', and 'invalid' appropriately, and must have your peer-edited first drafts attached!

7. Keep a written record of the questions and replies.
   This will be useful to the author, for revision.

8. At home, over the next week, please revise your paper to take into consideration the comments made by your fellow students (that is, your "peers"): Perhaps defend your claims better, or clarify statements that were misunderstood, etc. For help, see your instructor.

Suggested Grading Rubric for Position Paper #5

To the Instructor: For this assignment, I handed out the grading rubric when I gave the assignment, so that the students would know ahead of time how I was going to grade them. Whether or not you use my grading scheme, this information can be helpful to the students even for some of the earlier assignments.

For the grading rubric, please link to "Position Paper #5 Grading Rubric"