With the inevitability of "Luke, I am your father." for soeone watching Episode V in 2016 ... Hart goes straight to Mencken.
Perhaps the way the game can proceed is to never define what "great" is. There are, of course, some who deny there is any such thing as greatness while still being willing to say X's work saved my life. But there's "almost" no point trying to interact with people who get that way except to hope that we can recognize that superlatives and love are nearly as inseparable as eating food and defecating. There are settings in which these can be cast in twain but those settings tend to be rare and perhaps a bit unpleasant or unhealthy. :)