James H. Fetzer (1993) Van Brakel's Position Appears to be Incoherent. Psycoloquy: 4(14) Frame Problem (4)

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PSYCOLOQUY (ISSN 1055-0143) is sponsored by the American Psychological Association (APA).
Psycoloquy 4(14): Van Brakel's Position Appears to be Incoherent

VAN BRAKEL'S POSITION APPEARS TO BE INCOHERENT
Commentary on van Brakel on Ford & Hayes on the Frame-Problem

James H. Fetzer
Department of Philosophy
University of Minnesota
Duluth, MN 55812

jfetzer@ub.d.umn.edu

Abstract

Van Brakel's position appears to be incoherent. His argument is logically inconsistent; second, in denying my position, he denies his own; and, third, what he maintains is impossible is actually possible. Van Brakel's stance is thus invalid on logical, semantical and empirical grounds.

Keywords

Frame-problem, artificial intelligence, temporal logics, independent persistence, attention, Hume, dynamic frames, qualification problem.
1. There appear to be at least three reasons for disputing van Brakel's (1992) position (in his commentary on Ford & Hayes 1991). First, in 1.1, van Brakel asserts that there are three dimensions to the frame problem: [A] Which things change and which don't? [B] How can [A] be represented? and, [C] How can/do we reason about [A]? In 1.5, he sides with Hayes (1992) in denying that the frame problem is "the problem of induction in disguise." Yet in the very same paragraph he concedes that [A] "is definitely related to the induction problem"! Insofar as [B] and [C] are also "definitely" related to [A] by his own admission, all three dimensions of the frame problem van Brakel identifies are "definitely related to the problem of induction," which suggests that his position is not logically consistent.

2. Second, the problem of induction is precisely the problem of establishing a foundation for making inferences about the future on the basis of information about the past. This includes inferences about what WILL change and what WILL NOT change when events of various kinds occur. In maintaining that the frame problem is a special case of the problem of induction, not only do I not deny that it has other dimensions (of representation and of implementation) but I actively affirm it. Surely, if there is no answer to question [A] then there are no answers to [B] or [C], whose solutions presuppose a solution to [A]. Thus, in denying my position, van Brakel denies his own.

3. Third, in 2.0 and thereafter, van Brakel insists that the frame problem is a special case of "the problem of complete description." In 6.1, he elaborates, with the admonition that it is impossible to give necessary and sufficient conditions for the occurrence of an event or the definition of a concept. But even if it is logically impossible to provide a complete description of any single event (by virtue of its infinite relations to other events), which is true, it does not follow that necessary and sufficient causal conditions for events of specific kinds or necessary and sufficient definitional conditions for specific concepts cannot be advanced. That seems to be false.

4. Consider, for example, the definition of a "bachelor" as an "unmarried adult male," where the former is known as the definiendum and the latter as its definiens. The definiens formulates necessary and sufficient definitional conditions for its definiendum. Or consider the "lighting of a match." Such events typically occur as effects of causes consisting of "strikings of matches of specified chemical composition when they are dry and oxygen is present." The latter conditions appear to be individually necessary and jointly sufficient to bring about an occurrence of the kind described by the former, although other causes are of course possible.

5. If the considerations I have advanced above are well-founded, then, first, van Brakel's position appears to be logically inconsistent; second, in denying my position, he denies his own; and, third, what he maintains is impossible is actually possible. If van Brakel's position is logically inconsistent, then it cannot possibly be valid (on logical grounds). If in denying my position he is denying his own, then even if his position were valid it would be invalid (on semantical grounds). And if he is mistaken about the prospects for establishing conditions for events or for concepts, then he is also wrong (on empirical grounds). His position thus appears to be incoherent.

REFERENCES

Ford, K.M. and P.J. Hayes (1991) Reasoning Agents in a Dynamic World: The Frame Problem. Greenwich: JAI Press.

Hayes, P.J. (1992) Summary of "Reasoning Agents in a Dynamic World: The Frame Problem" (Ford & Hayes 1991, Eds.) PSYCOLOQUY 3(59) frame-problem.1

van Brakel, J. (1992) The Complete Description of the Frame Problem. PSYCOLOQUY 3(60) frame-problem.2


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