Also, for any individual and any counterpart relation, there is the set of that individual together with all its counterparts, and this is a less strict sort of haecceity".
True enough, we can only refer to Quine's haecceity by referring, at least obliquely, to Quine.
However, all that follows from that is that if Quine hadn't existed, it would not have been possible to refer to his haecceity, at least, not by means of a gerund involving a proper name of Quine.
For Quine is the very component that distinguishes being identical with Quine from every other haecceity, and hence he appears to be essential to its identity.
(The term 'individual essence' is sometimes used to denote such a haecceity.
Referring back to our Alien example, then, the proposition that it is possible that there are Aliens, ◇∃xAx, is true on this account if and only if there is a possible world w and a haecceity e such that 'A' applies to e at w, i.e., if and only if the property [being an Alien] and e are coexemplified in w.
Then, under the denotation assignment in question, '~Px' is true at a world w just in case Socrates's haecceity hs is coexemplified with the property of failing to be a philosopher at w.
However, since no such haecceity is exemplified in the actual world, i.e., since there is no such haecceity in its essential domain, nothing (i.e., nothing actual) is a possible Alien, that is, ∃x◇Ax is false.
(A VI iv 1540 41/AG 41) Leibniz's invocation of the Scotist notion of a haecceity is intriguing.
On this view, one gets a first-person belief by believing a proposition including his or her own haecceity, and one gets a present-time belief by believing a proposition involving the haecceity of a moment of time at the time in question.
In contrast to more modern accounts of the problem of individuation, Scotus holds that the haecceity explains more than just the distinction of one substance from another.
