Modal Copulation and Satisfaction. by Jessica Leech
This kind of approach adheres to the intuition that de re modality is somehow involved with the relation between an object and a property, rather than being involved in the inception of new predicates and new properties. This can be illustrated by the difference between asking, ‘Is Socrates necessarily wise, or is he just contingently so?’, and asking which of two properties Socrates has, (contingent) wisdom or necessary wisdom?
McGinn, in his book Logical Properties, presents such a copula modifier account of modality. He claims that a statement of the form “a is [modally] F” is true just when a [modally] satisfies “is F”. So, for example, “Socrates is necessarily wise” is true iff Socrates necessarily satisfies the predicate “is wise”. Modal satisfaction is in turn explained in terms of modal instantiation. So, Socrates necessarily satisfies “is wise” iff Socrates necessarily instantiates wisdom.
The challenge for modal copula accounts that employ “modal satisfaction” is to flesh out this new semantic notion. McGinn’s strategy is to appeal to modes of instantiation. He claims that there are two and only two modes of instantiation, necessary and contingent. Our statements might leave this as neutral, e.g. “Socrates is wise”, but at the worldly level, where we find Socrates and wisdom, if they bear the instantiation relation to each another, then they bear that relation in one or other mode.
The problem with this theory is that there is no way to accommodate mere possibility. Firstly, it is prima facie unclear how one could begin to understand possible instantiation as a mode of instantiation, where there need be no actual instantiation, but there is only mere possibility. More worrying, a contradiction can be generated:
(1) “Socrates is possibly foolish” is true.
(2) So Socrates contingently instantiates foolishness.
(3) So, Socrates instantiates foolishness.
(4) “Socrates is not foolish” is true.
(5) So Socrates does not instantiate foolishness.
In order to give the copula modifier account of modality fair trial, we cannot follow McGinn’s lead. We must either find an alternative way to understand modal satisfaction, or find a better way to make sense of copula modification than in terms of modification of satisfaction.