Don't divorce Nature. Marcus Aurelius 2.16

Marcus Aurelius believes that purpose is essential to life. Life according to nature is not, for him, an aimless journey. <Greek>.

Ὑβρίζει ἑαυτὴν ἡ τοῦ ἀνθρώπου ψυχὴ μάλιστα μέν, ὅταν ἀπόστημα καὶ οἷον φῦμα τοῦ κόσμου, ὅσον ἐφ̓ ἑαυτῇ, γένηται· τὸ γὰρ δυσχεραίνειν τινὶ τῶν γινομένων ἀπόστασίς ἐστι τῆς φύσεως, ἧς ἐν μέρει αἱ ἑκάστου τῶν λοιπῶν φύσεις περιέχονται. ἔπειτα δέ, ὅταν ἄνθρωπόν τινα ἀποστραφῇ ἢ καὶ ἐναντία φέρηται ὡς βλάψουσα, οἷαί εἰσιν αἱ τῶν ὀργιζομένων. τρίτον ὑβρίζει ἑαυτήν, ὅταν ἡσσᾶται ἡδονῆς ἢ πόνου. τέταρτον, ὅταν ὑποκρίνηται καὶ ἐπιπλάστως καὶ ἀναλήθως τι ποιῇ ἢ λέγῃ. πέμπτον, ὅταν πρᾶξίν τινα ἑαυτῆς καὶ ὁρμὴν ἐπ̓ οὐδένα σκοπὸν ἀφιῇ, ἀλλ̓ εἰκῇ καὶ ἀπαρακολουθήτως ὁτιοῦν ἐνεργῇ, δέον καὶ τὰ μικρότατα κατὰ τὴν ἐπὶ τὸ τέλος ἀναφορὰν γίνεσθαι· τέλος δὲ λογικῶν ζῴων τὸ ἕπεσθαι τῷ τῆς πόλεως καὶ πολιτείας τῆς πρεσβυτάτης λόγῳ καὶ θεσμῷ.

The human soul tears herself whenever she separates from the world that lies over her, becoming a blight upon its beauty. Irritation at something that happens is one separation from Nature, which contains within herself the smaller nature of each different thing. Another separation takes place when the soul turns away from another person, or carries herself against another with intent to harm: this is the way of angry souls, stirred to wrath. The soul also tears herself every time she is vanquished by pleasure or toil, and again whenever she pretends, doing or saying what is deliberately false and untruthful. Yet another separation occurs when she allows some habit or desire to go unwatched, abandoning it to operate at random and without consequence. Even the smallest things require their purpose. The purpose of rational animals is to follow the reckoning and rule of the most ancient city, and her way of life.