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2 ideas
| 12595 | We have a theory of logic (implication and inconsistency), but not of inference or reasoning [Harman] |
| Full Idea: There is as yet no substantial theory of inference or reasoning. To be sure, logic is well developed; but logic is not a theory of inference or reasoning. Logic is a theory of implication and inconsistency. | |
| From: Gilbert Harman ((Nonsolipsistic) Conceptual Role Semantics [1987], 12.2.2) | |
| A reaction: One problem is that animals can draw inferences without the use of language, and I presume we do so all the time, so it is hard to see how to formalise such an activity. |
| 12597 | I might accept P and Q as likely, but reject P-and-Q as unlikely [Harman] |
| Full Idea: Principles of implication imply there is not a purely probabilistic rule of acceptance for belief. Otherwise one might accept P and Q, without accepting their conjunction, if the conjuncts have a high probability, but the conjunction doesn't. | |
| From: Gilbert Harman ((Nonsolipsistic) Conceptual Role Semantics [1987], 12.2.2) | |
| A reaction: [Idea from Scott Soames] I am told that my friend A has just won a very big lottery prize, and am then told that my friend B has also won a very big lottery prize. The conjunction seems less believable; I begin to suspect a conspiracy. |