That had nothing to do with his philosophical view on humanity though. It was merely a "scientific" way of proving to Dante that it couldn't possibly be meningitis, the reason why he didn't remember anything, because he's physiologically unable to suffer from it.
Actually, it does. Vergil's dialogue subtly makes it clear early on that he sees humans as weak, and that Nephilim are superior.
Also a quote from the tvtropes character page: "When Dante meets him for the first time, he tells him they are fighting for humanity. Dante says he doesn't give a **** about mankind, and rather than try to convince him humans deserve to be free, Vergil smoothly changes his argument to make the stakes more personal. The freedom of humankind doesn't come up again as a worthwhile goal. "