I've never encountered a well written business layer. Any advice?

Question

I look around and see some great snippets of code for defining rules, validation, business objects (entities) and the like, but I have to admit to having never seen a great and

Answer 1

I imagine this is because business logic, as a general rule, is arbitrary and nasty. Garbage in, garbage out.

Also, most of the really good business layers are most probably proprietary. ;-)