Don Ringe is a very, very smart guy. In his discipline, only a very smart guy writes this:
In the first place, if you want “reality-based” answers, take a scientific approach. Science may or may not reveal the existence of an objectively real world out there, but it does give results that can be replicated and answers that can be proved by anyone who knows how the system works. That’s good enough for me because I think it’s the best we can hope for. If people find specific scientific conclusions ideologically inconvenient, that’s their problem.Thus, you should read his discussion, on LanguageLog, of the languages of Europe prior to the arrival of Indo-European and the eventual spread of our linguistic parent.