In one sense 'there are' both universals and material objects, in another sense there is no such thing as either: statements about each can usually be analysed, but not always, nor always without remainder.
Talk with M. Hermite. He never evokes a concrete image, yet you soon perceive that the more abstract entities are to him like living creatures.
Adam and Eve are like imaginary numbers, like the square root of minus one... If you include it in your equation, you can calculate all manners of things, which cannot be imagined without it.
But in the prevalent discussion of classes, there are illegitimate transitions to the notions of a 'nexus' and of a 'proposition'. The appeal to a class to perform the services of a proper entity is exactly analogous to an appeal to an imaginary terrier to kill a real rat. Process and Reality
... the laws of physics and of logic ... the number system ... the principle of algebraic substitution. These are ghosts. We just believe in them so thoroughly they seem real.
Abstraction is a mental process we use when trying to discern what is essential or relevant to a problem; it does not require a belief in abstract entities.
If all sentient beings in the universe disappeared, there would remain a sense in which mathematical objects and theorems would continue to exist even though there would be no one around to write or talk about them. Huge prime numbers would continue to be prime, even if no one had proved them prime.
Such words as "society" and "community" are likely to be misleading, for they have a tendency to make us think there is a single thing corresponding to the single word.
