Iamblichus, Protrepticus 51:
“Humans are the most noble of the animals, as is clear from the fact that they are born both from and directed toward nature. This it is for the sake of which nature and god made us. When Pythagoras was asked about the purpose for which humans were created, he said, ‘To look upon the heavens’, and he said that he himself was an observer of nature, and had come into life for that purpose. They also say that Anaxagoras was asked for what reason someone might choose to be born and to go on living, and he responded, ‘in order to watch the heavens, and the stars and moon and sun’, as though nothing else in the world were worth consideration.”
τιμιώτατον δέ γε τῶν ἐνταῦθα ζῴων ἄνθρωπός ἐστιν, ὥστε δῆλον ὅτι φύσει τε καὶ κατὰ φύσιν γέγονε. καὶ τοῦτό ἐστι τῶν ὄντων οὗ χάριν ἡ φύσις ἡμᾶς ἐγέννησε καὶ ὁ θεός. τί δὴ τοῦτό ἐστι Πυθαγόρας ἐρωτώμενος, ‘τὸ θεάσασθαι’ εἶπε ‘τὸν οὐρανόν’, καὶ ἑαυτὸν δὲ θεωρὸν ἔφασκεν εἶναι τῆς φύσεως καὶ τούτου ἕνεκα παρεληλυθέναι εἰς τὸν βίον. καὶ ᾿Αναξαγόραν δέ φασιν εἰπεῖν ἐρωτηθέντα τίνος ἂν ἕνεκα ἕλοιτο γενέσθαι τις καὶ ζῆν, ἀποκρίνασθαι πρὸς τὴν ἐρώτησιν· ὡς ‘τοῦ θεάσασθαι [τὰ περὶ] τὸν οὐρανὸν καὶ <τὰ> περὶ αὐτὸν ἄστρα τε καὶ σελήνην καὶ ἥλιον’, ὡς τῶν ἄλλων γε πάντων οὐδενὸς ἀξίων ὄντων.