φιλοσοφητέον

A. one must pursue knowledge, Pl. Euthd. 288d, Isoc. 15.285, Epicur. Ep. 3p.59U., Cic. Att. 1.16.13, Iamb. Protr. 12; ἥντινα [φιλοσοφίαν] φ. Luc. Herm. 45; φ. περὶ μουσικῆς Ath. 14.632b, cf. Plot. 3.5.2.