Τῶν οὐσιῶν ὅσαι φύσει συνεστᾶσι, τὰς μὲν <λέγομεν> ἀγενήτους καὶ ἀφθάρτους εἶναι τὸν ἅπαντα αἰῶνα, τὰς δὲ μετέχειν γενέσεως καὶ φθορᾶς. συμβέβηκε δὲ περὶ μὲν ἐκείνας τιμίας οὔσας καὶ θείας ἐλάττους ἡμῖν ὑπάρχειν θεωρίας (καὶ γὰρ ἐξ ὧν ἄν τις σκέψαιτο περὶ αὐτῶν, καὶ περὶ ὧν εἰδέναι ποθοῦμεν, παντελῶς ἐστὶν ὀλίγα τὰ φανερὰ κατὰ τὴν αἴσθησιν), περὶ δὲ τῶν φθαρτῶν φυτῶν τε καὶ ζῴων εὐποροῦμεν μᾶλλον πρὸς τὴν γνῶσιν διὰ τὸ σύντροφον· πολλὰ γὰρ περὶ ἕκαστον γένος λάβοι τις ἂν τῶν ὑπαρχόντων βουλόμενος διαπονεῖν ἱκανῶς. ἔχει δ’ ἑκάτερα χάριν. τῶν μὲν γὰρ εἰ καὶ κατὰ μικρὸν ἐφαπτόμεθα, ὅμως διὰ τὴν τιμιότητα τοῦ γνωρίζειν ἥδιον ἢ τὰ παρ’ ἡμῖν ἅπαντα, ὥσπερ καὶ τῶν ἐρωμένων τὸ τυχὸν καὶ μικρὸν μόριον κατιδεῖν ἥδιόν ἐστιν ἢ πολλὰ ἕτερα καὶ μεγάλα δι’ ἀκριβείας ἰδεῖν· τὰ δὲ διὰ τὸ μᾶλλον καὶ πλείω γνωρίζειν αὐτῶν λαμβάνει τὴν τῆς ἐπιστήμης ὑπεροχήν, ἔτι δὲ διὰ τὸ πλησιαίτερα ἡμῶν εἶναι καὶ τῆς φύσεως οἰκειότερα ἀντικαταλλάττεταί τι πρὸς τὴν περὶ τὰ θεῖα φιλοσοφίαν.
(Aristotle, Part. An. 644b23-645a4)
Of all beings naturally composed, some are ungenerated and imperishable for the whole of eternity, but others are subject to coming-to-be and perishing. It has come about that in relation to the former, which possess value—indeed divinity—the studies we can make are less, because both the starting-points of the inquiry and the things we long to know about present extremely few appearances to observation. We are better equipped to acquire knowledge about the perishable plants and animals because they grow beside us: much can be learned about each existing kind if one is willing to take sufficient pains. Both studies have their attractions. Though we grasp only a little of the former, yet because the information is valuable we gain more pleasure than from everything around us, just as a small and random glimpse of those we love pleases us more than seeing many other things large and in detail. But the latter, because the information about them is better and more plentiful, take the advantage in knowledge. Also, because they are closer to us and belong more to our nature, they have their own compensations in comparison with the philosophy concerned with the divine things. (tr. David M. Balme)