Perfecting humanity. Marcus Aurelius 5.16

Marcus exhorts himself to imagine the life, and character, he desires to present. We live by imagining and then acting upon our imagination, which is shared with others like us, in our case. This capacity for creating and imparting to others manifests ultimately in shared understanding, or (in Stoic terms familiar to Marcus) logos. Unamuno echoes this take on reason (razón, ratio) in Life 2.6.

Οἷα ἂν πολλάκις φαντασθῇς, τοιαύτη σοι ἔσται ἡ διάνοια· βάπτεται γὰρ ὑπὸ τῶν φαντασιῶν ἡ ψυχή. βάπτε οὖν αὐτὴν τῇ συνεχείᾳ τῶν τοιούτων φαντασιῶν· οἷον, ὅτι ὅπου ζῆν ἐστιν, ἐκεῖ καὶ εὖ ζῆν· ἐν αὐλῇ δὲ ζῆν ἐστιν· ἔστιν ἄρα καὶ εὖ ζῆν ἐν αὐλῇ. Καὶ πάλιν, ὅτι οὗπερ ἕνεκεν ἕκαστον κατεσκεύασται, πρὸς τοῦτο κατεσκεύασται· πρὸς ὃ δὲ κατεσκεύασται, πρὸς τοῦτο φέρεται· πρὸς ὃ φέρεται δέ, ἐν τούτῳ τὸ τέλος αὐτοῦ· ὅπου δὲ τὸ τέλος, ἐκεῖ καὶ τὸ συμφέρον καὶ τὸ ἀγαθὸν ἑκάστου· τὸ ἄρα ἀγαθὸν τοῦ λογικοῦ ζῴου κοινωνία. ὅτι γὰρ πρὸς κοινωνίαν γεγόναμεν, πάλαι δέδεικται· ἢ οὐκ ἦν ἐναργὲς ὅτι τὰ χείρω τῶν κρειττόνων ἕνεκεν, τὰ δὲ κρείττω ἀλλήλων; κρείττω δὲ τῶν μὲν ἀψύχων τὰ ἔμψυχα, τῶν δὲ ἐμψύχων τὰ λογικά.

What you imagine constantly: this will become your mind. For the soul is steeped, dyed, and tempered in our fantasies. Baptize her, then, in illusions like those that follow. First, that wherever it is possible to live, there too it is possible to live well. Life at court is possible, so it must be possible to live well, even there. Another illusion to cultivate: that everything is prepared for the purpose its preparation serves. Preparation entails purpose, and purpose entails end, the perfection of what is prepared. Wherever perfection lies, there you find what is needful and good in each thing. Fellowship with others is the good sought by a logical animal, one that uses reason. For this fellowship we were born, as ancient experience has already shown. Isn't it clear that better things and worse always exist for the sake of one another, each to provide what the other requires? Living things are better than dead, and the fellowship of the logical surpasses mere animal life.