Monday, March 26, 2012

Analogy and properties

Spot is a cat and Tob is a table. Spot has four legs and Tob has four legs. But "has four legs" in these two claims is analogical. The two claims are ultimately grounded in similar sorts of facts, but not in exactly similar sorts of facts. What makes Spot have four legs is that he has certain organs of locomotion, four in number. What makes Tob have four legs is that it has certain supporting parts, four in number.

Suppose we start talking about legs with people and cats, and only later move on to tables. Then we are analogically extending the concept of quadruple leggedness to pick out that feature that in tables is similar to what quadruple leggedness is or would be like in people and cats.

We could (in the sense corresponding to metaphysical possibility) use a very well trained cat that has particularly rigid ears and tail as a three legged table, by standing it up on on the ears and tail and putting a dish on the tummy. That cat/table would have four legs in the cat sense and three legs in the table sense. We would then say that this object has four legs qua cat and three legs qua table. On my adverbial ontology, the clear way to express this is to say that the object is a cat four-leggedly and a table three-leggedly.

But if this is right, then we should say similar things about Spot and Tob. Spot is a cat four-leggedly while Tob is a table four-leggedly. And these adverbs do different, albeit analogous, things to being a cat and being a table.

The predicate "has four legs" is adverbial. Something satisfies it in virtue of being something or other in a four-legged manner.

There had better be some non-adverbial predicates. Otherwise, we will have a vicious regress or circularity.

I conjecture that all accidental predication ("accidental" in the medieval, not the modal, sense) is adverbial and analogical in this way. One needs to, as it were, fill in an underlying predicate, the "G" in "is a G Fly", in order to make sense of "is F".

The line of thought is inductive: all the accidental predicates that I can think of are analogical in this way.

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