ἔτι τὸ κινοῦν το ἄπειρον τί ἐστιν; εἰ μὲν γὰρ αὐτὸ ἑαυτό, ἔμψυχον ἔσται. τοῦτο δὲ πῶς δυνατόν, ἄπειρον εἶναι ζῷον;
What moreover is it which moves the infinite? If it moves itself, it must be alive. Yet how could this be possible, that there should be an infinite animal?
Aristotle, On the Heavens 1.7.