Descriptive (Not Prescriptive) Rules

“Consider the planets. They are not solving differential equations as they swing around the sun. They are not following any rules at all; but their behavior is nonetheless lawful, and to understand their behavior we find a formalism — in this case — differential equations — which expresses their behavior according to a rule” (Dreyfus, 189).

In other words, rules are descriptive, not prescriptive. Given the proper descriptive rules, computer scientists and mathematicians can model the movements of the planets, even though the planets never do any mathematical calculations. In a similar way, given the proper descriptive rules, computer scientists might be able to model the movements of a human chess player and (perhaps) the “movements” of a human interlocutor. But the planets, the chess player, and the interlocutor need not have anything whatsoever to do with the formal systems that describe them. This is the fallacy that stupefication helps us skirt and which traditional GOFAI often fails to skirt.

Thus, the kind of language games mentioned at the end of my previous post, and which we’ll talk about later, need not be games that human beings play and need not be governed by rules that govern human linguistic practices.

Citations:

Dreyfus, Hubert L.  What Computers Can’t Do. New York : Harper and Row, 1979.