Lifelong learning. Marcus Aurelius 4.30

Like Socrates, Marcus is not attached to any particular lesson. He does not pursue philosophy to achieve stable information (the kind you can cleave to or abide in, cf. ἐμμένειν here), but to navigate the world of shifting uncertainty and ignorance that is our mortal lot.

Ὁ μὲν χωρὶς χιτῶνος φιλοσοφεῖ, ὁ δὲ χωρὶς βιβλίου. ἄλλος οὗτος ἡμίγυμνος· ἄρτους οὐκ ἔχω, φησί, καὶ ἐμμένω τῷ λόγῳ. ἐγὼ δὲ τροφὰς τὰς ἐκ τῶν μαθημάτων ἔχω καὶ οὐκ ἐμμένω.

Some pursue philosophy without clothes, while others avoid books. Here's a really clever fellow who splits the difference, going half-clad. "No food for me!" he says. "I cleave only to the Word, to Theory and to rational Law." As for myself: I have many meals' worth of lessons, and I cleave to none of them.