gre ed. Burnet 1903 286a1-286bδιὸ δεῖ μελετᾶν λόγον ἑκάστου δυνατὸν εἶναι δοῦναι καὶ δέξασθαι: τὰ γὰρ ἀσώματα, κάλλιστα ὄντα καὶ μέγιστα, λόγῳ μόνον ἄλλῳ δὲ οὐδενὶ σαφῶς δείκνυται, τούτων δὲ ἕνεκα πάντ᾽ ἐστὶ τὰ νῦν λεγόμενα. ῥᾴων (286b) δ᾽ ἐν τοῖς ἐλάττοσιν ἡ μελέτη παντὸς πέρι μᾶλλον ἢ περὶ τὰ μείζω.
eng tr. Jowett 1817-1893and therefore we ought to train ourselves to give and accept a rational account of them; for immaterial things, which are the noblest and greatest, are shown only in thought and idea, and in no other way, and all that we are now saying is said for the sake of them. Moreover, there is always less difficulty in fixing the mind on small matters than on great.
http://www2.hf.uio.no/common/apps/permlink/permlink.php?app=polyglotta&context=record&uid=2a3d8059-cfdd-11e7-8793-0050569f23b2
