As I have admitted elsewhere, I am a dunce when it comes to philosophy. So my answer is going to be relentlessly positivist.
If we do not discriminate between entities in the world, we do away with any possibility of predicate logic. And in language, we do away with nouns.
If we do not discriminate between properties in the world, which have distinct intensions and extensions, we do away with propositional logic. And in language, we do away with verbs and adjectives.
With neither predicates nor propositions, we could still attempt to reason with what’s left. But what’s left would be so God Almighty fluffy and hippie, that I’d be reluctant to call it reasoning as I know it.
Why yes. Fluffy and hippie are positivist terms.