Yes, and that's the doctrine of first sale: you can do what you like with a copy you own, besides make additional unauthorized copies.

As such, libraries operate within the law and within the spirit of copyright, while file sharing doesn't.

You can certainly object to the spirit of copyright as expressed here, but there's nothing inconsistent about supporting it, and supporting public libraries.

You say "only" as if this isn't an important distinction in terms of creating value for a copyrighted work.

Confused: you can 'return' the movie AND keep a copy, which you distribute widely thus ruining any chance of the creator profiting by their work.

Can't do that with the physical book. Not for free anyway.

You can scan the book and distribute digital copies of it for free. The only investment is time required to scan the books.

You can also steal a book from the library under your jacket, and then you don't have to return it. It doesn't mean it's legal or right.

I was just countering his point on copying physical books: "Can't do that with the physical book. Not for free anyway."

Stealing a book doesn't amount to copying the book and returning it.