De Partibus Animalium
Οὐ γὰρ ἀργίας ὤνιον ἡ ὑγίεια καὶ ἀπραξίας, ἅ γε δὴ μέγιστα κακῶν ταῖς νόσοις πρόσεστι, καὶ οὐδὲν διαφέρει τοῦ τὰ ὄμματα τῷ μὴ διαβλέπειν καὶ τὴν φωνὴν τῷ μὴ φθέγγεσθαι φυλάττοντος ὁ τὴν ὑγίειαν ἀχρηστίᾳ καὶ ἡσυχίᾳ σῴζειν οἰόμενος → For health is not to be purchased by idleness and inactivity, which are the greatest evils attendant on sickness, and the man who thinks to conserve his health by uselessness and ease does not differ from him who guards his eyes by not seeing, and his voice by not speaking
Wikipedia EN
Parts of Animals (or On the Parts of Animals; Greek Περὶ ζῴων μορίων; Latin De Partibus Animalium) is one of Aristotle's major texts on biology. It was written around 350 BC. The whole work is roughly a study in animal anatomy and physiology; it aims to provide a scientific understanding of the parts (organs, tissues, fluids, etc.) of animals and asks whether these parts were designed or arose by chance.