In a recent departmental seminar Rob Adams gave an excellent paper on existence. In the paper he argued for an Aristotelian schema for existence such that 'for anything to exist is for it... to have all its essential properties'. For example, when I die I will no longer exist, assuming that one of my essential properties is being alive. He went on to discuss objects that did exist but no longer exist, as well as objects that never existed and objects that could never exist.
I confess to not fully understanding the implications of all that he said, but the particular point that I want to mention came about two thirds of the way into the paper. Adams suggested that he was skeptical of the truth of the law of the identity of indiscernibles (that for any x and for any y, if x is indiscernible from y, then x is identical to y).
He then went to talk about shares in a company. Shares are examples of what he called ‘merely intentional’ objects, which I took to be those objects that exist only in virtue of our mental intentions towards them. (In contrast, my car is an intentional object, as when I think that I like my car, but it is also a physical object with a spatio-temporal location, so is not merely intentional.) If I understood him correctly, he was using shares as an example of indiscernible objects that are nevertheless non-identical. If I buy 50 shares from company XYZ, and then ask my broker to sell one, it would be very odd of me (his example) if I later complained that he had sold my favorite one.
Is this a genuine counter example to the identity of indiscernibles? I'm not entirely sure that he meant it to be, but if he did, and it is, it seems surprising that it has not been pointed out before.
My immediate thought was that when I have 50 shares, I do not have 50 individual ‘merely intentional’ objects, but rather one object with a relative value of 50. If I gave one share to my brother, he would have an object with a relative value of one and I would have an object with a relative value of 49. We would have created a new entity with the giving of the gift, but that would be no problem since they are merely intentional objects and so can be created and destroyed without any difficulty at all.
The worry here, however, is in taking this line I am being motivated by a prior commitment to the law of the Identity of Indiscernibles to explain away the shares example.
What do you think?