Earlier quoted context omitted.
In a mathematical world you operate with abstract objects. In the real word - you need to abstract things; before that everything is unique; after that - well, depends on your abstraction. So unless you talk about mathematics, things can be more or less unique.
This is a excellent and subtle comment. You seem like someone with a tolerance for philosophical nit-picking. Please forgive me if I'm mistaken. Instead of saying every thing is unique we could simply say that there is no thing . A thing is itself an abstraction. The concrete world is without inherently distinct thing s. We must abstract thing s for "unique" to describe some thing at all. As you implied, this process…
From a common sense perspective, it's obvious that there are things. Sure, you can point out the flux and decay of all entities, but still, this table here is a coherent thing even if it's made from parts in a temporary arrangement.
In some sense, philosophy itself is destroyed when you go down the path of denying objects, since philosophy crucially deals with concepts, and concepts are "thought objects."
Harman describes two modes of denying objects: undermining and overmining. Undermining is the tendency to say "really, this object is just a composition of these other particles," while overmining is the tendency to say "this object is just a modulation in a grand monistic entity."
Instead of that, he recommends an ontology of objects that's pretty interesting and fun to read about. He would, I think, agree that objects are unique in that they are (in programmer jargon) "pointer equal" to only themselves... and each real object, for that reason, has an infinity of potential that's never exhausted by any "arbitrary" perception of it... yet still, we perceive other objects not directly, but through aesthetic caricatures, and on that level you might have different degrees of uniqueness.