Some Thoughts on the Identity of Indiscernibles
The identity of indiscernibles (IoI) is a principle which is controversial in contemporary analytic philosophy, but I can’t understand why. I’m fully aware of the fact that philosophers are known for holding flatly absurd positions, and it may be the case that the reason many philosophers reject IoI. I’d like to provide reason why we ought to accept this principle, but first a formulation is in order.
Identity of Indiscernibles (IoI): if x is F where F is all the true predicates of x, and y is F, the x and y are identical.
To my mind, this is obviously true, but since it is so controversial, I’ll provide some reason for accepting it. The main response to the IoI is that distinctness can be a primitive, but this seems weak, to my mind, as this would violate the PSR, which has plenty of reason behind it (see here: https://link.springer.com/article/10.1007/s11098-020-01482-3, https://www.amazon.com/Principle-Sufficient-Reason-Reassessment-Philosophy/dp/0521184398, https://www.youtube.com/watch?v=wuSxB2JNseY, http://alexanderpruss.com/papers/LCA.html, https://www.youtube.com/watch?v=bHw61T-zaeQ&t=3412s). Distinctness certainly seems to be a bounded fact, which is a fact that has limited conceptual content, and bounded facts need explanations as Pruss and Koons have shown and so distinctness simply can't be a primitive. Moreover, the supposed counterexamples to the principle are mere thought experiments that purport to show that there are conceivable worlds where the IoI is violated, but conceivability is only a fallible guide to possibility and when we have good reason for rejecting the possibility of conceivable worlds, as we do in this case because of the PSR, we ought to do so. Furthermore, these counterexamples have disastrous metaphysical consequences as Michael Della Rocca has pointed out (see here: https://www.academia.edu/4233574/Two_Spheres_Twenty_Spheres_and_the_Identity_of_Indiscernibles).
A couple of weeks ago, while watching Schmid's stuff on classical theism, I came across an argument against the Identity of Indiscernibles that runs as follows:
ReplyDeleteSay x and y are distinct things, so by the Identity of Indiscernibles they have some distinct features. This seems to lead into an infinite regress, because you can now ask "in virtue of what are those features of x and y distinct?" If nothing, then there is primitive individuation. Otherwise, we're off to an infinite regress. Thus, we must bottom out in primitive individuation.
To me, this argument sounds a lot like the problem of the One and the Many lol. Your thoughts on it?
Thanks for the comment. Is this argument from Joe? This is actually a pretty interesting argument. I'm not sure if the infinite regress that ensues is that problematic, especially among finite things. If Aristotle is right that matter is potentially infinitely divisible, which I think he is, then such a regress in material things is not surprising. For other finite things that are immaterial like angels, the fact that an angel has a certain essence while another has a different one would just be the final explanation. The fact that essences are distinct in the sense that identity is primitive, but it's not brute, so that's not really an issue. You can say the same thing for material things if you don't like Aristotle too. God Bless.
DeleteTo sum up what I said before, that which individuates can be primitive without individuation being primitive.
DeleteNo clue if it’s from Schmid, I just found it in one of his videos.
DeleteIt seems that, due to essences being the principle of distinction, they can ground distinction. As you said, they can be what differentiates one angel from another. Essences thus differentiate by virtue of themselves (not anything else).
This would then seem to apply to all material thing, as all things have essences. Thus, the infinite regress need not apply to material things as well.
I'm not quite sure I see the problem, maybe I've been misunderstanding something. But if there are such things as X and Y then the question as to why there are those things that possess different features are just X and Y themselves. Where exactly is the infinite regress supposed to come from? To use Armstrong's language, suppose that the notion of individuation is either basic, a thin particular instantiated within the thick particular or it's something derived from the thick particular itself. In neither case do I see the problem. True, in the first case it's primitive. Does he use that as an argument against classical theism? This wouldn't work since that which does the individuation is dependent upon existence and it's priority to its own act of existence only entails that the individuality is basic within that specific creature.
DeleteIn the second case, it's derived from the different properties (thin particulars) that are instantiated, either as a relation within a bare particular or as an instant of a universal within a constituent ontology. The different properties ground that what differentiates X and Y. And even if the properties are the same, I'd follow Rob Koons that it's the specific instantiation of the properties that are doing the individuation. You could also say it's the specific instance of prime matter.
I really lack the insight here. Where is the regress supposed to come from and what are its supposed consequences? And what are the supposed consequences of the individuation being primitive?
Good points :)
DeleteYou can just make a distinction between the substance and accidents of thing and then just say that these changes to Socrates are accidental and not substantial and this is in keeping with Leibniz's law. God Bless :)
ReplyDeleteDo you think that there are intrinsic pure accidents? If so, then you cannot hold to Leibniz's Law. If not, then you are committed to the non-existence of intrinsic change.
ReplyDelete