The two Greeks were easy, I imagine. Plato and Aristotle, of course. The Germans are a little more difficult, but eventually you will turn up Leibniz, Kant and Marx. There is only one possible Scotsman, Hume. Only one possible Frenchman, Descartes. The Austrian must be Wittgenstein. The Italian is the hard one for most people. That's partly because they forget about him, and partly because they don't know that he is Italian. It's Thomas Aquinas.