In his book on quantum mechanics in the chapter on perturbation theory Dirac says in a footnote:
A system with only one stationary state belonging to each energy-level is often called non-degenerate and one with two or more stationary states belonging to an energy-level is called degenerate, although these words are not very appropriate from the modern point of view.
I have two questions about this:
1) Why did Dirac deem the terms (non-)degenerate inappropriate?
2) Why do we, with our even more modern point of view, still use them?