I was raised on the rhetoric of "greatness" like any other whitebread suburban boy. I have since gone through an education sentimentale about the whole greatness thing, finding the word great to be a hollow sham used by politicians, for the most part.
Adam is learning "encadrement" in his school - which is basically a way of teaching that there are three relations between a whole number x and another number - greater, lesser, or equal. Here, the use of great is all on the surface. It is the transposition from the realm of quantity to the realm of quality that we run into problems.
There have been psychological experiments done to see if transitivity holds among taste preferences - as was once assumed as an axiom by economists. This means that if one prefers x to y and y to z, then you should prefer x to z. However, it turns out that preferences are entangled. Some people do express their preferences in a transitive order, and some don't. This happens regardless of the objects of the preference - whether poltiical candidates or vegetables.
Still, in the aesthetic realm, a form of transitivity is assumed, so that if Shakespeare is greater than Shelley and Shelley is greater than Musset, than Shakespeare must be greater than Musset. Yet this view of greatness does seem, to me, rather bogus. It isn't that I can't predict, from a subjects list of favorite auithors, for instance, other authors this subject might like - but the prediction is hedged with contingencies. I recently bought as a gift the letters of Chekhov for a friend. This friend also liked Stendhal - is a real Stendhalian. I thought Chekhov's form of tough liberalism would appeal. It did! So then I gave this friend Radetzky's March. Joseph Roth's novel seems to me to have so many Stendhalian motifs, though of course with a different twist. I was sure that this was a good gift. Error!
I find, as I grow older and closer to death, that superlatives mean less and less - they organize less and less of what I think about, say, literature or politics or history or philosophy. I have a feeling that this agnosticism about superlatives and their correlates in the world is not a popular view, because who wants to toss out greatness?
But to me, greatness is a rip off.