Full Idea
Three main reasons for thinking properties exist: the one-over-many argument (that a type can have many tokens), the reference argument (to understand predicates and singular terms), and the quantification argument (that we quantify over them).
Gist of Idea
We accept properties because of type/tokens, reference, and quantification
Source
Douglas Edwards (Properties [2014], 1.1)
Book Reference
Edwards,Douglas: 'Properties' [Polity 2014], p.1
A Reaction
[Bits in brackets are compressions of his explanations]. I don't find any of these remotely persuasive. Why would we infer how the world is, simply from how we talk about or reason about the world? His first reason is the only interesting one.