What are the differences between linguistics and philology?

Philology is what linguists think they are above doing, and they are boneheads for doing so.

Philology was the study of language in its literary context; so it was confined to written language, and historical linguistics, both of which have become decidedly old fashioned. So when the Old Man of Modern Greek  Linguistics, Georgios Chatzidakis, said (in impeccable Puristic Greek) πᾶς μὴ φιλολογῶν οὐ γλωσσολογεῖ, “If you’re not doing philology, you’re not doing linguistics”, the post-Saussurean mob guffaw.

I wouldn’t be guffawing if I was part of a movement that gave us the Chomskyan view of language.

The point of philology is not just the narrowly literary context of language, after all. When philology is being informed by archaeology, we’ve moved beyond literature. It is the cultural context of language, of which literature is one component. And Old Man Chatzidakis was right: if you’re studying language with no attention to the cultural norms it is situated in, you’re studying just an idealisation of language—and you’re going to miss things.