ἀσκεῖν περὶ τὰ νοσήματα δύο, ὠφελεῖν ἢ μὴ βλάπτειν → strive, with regard to diseases, for two things — to do good, or to do no harm | as to diseases, make a habit of two things — to help, or at least, to do no harm
unyielding: P. ἰσχυρός, V. ἔμπεδος.
firm, secure: P. and V. βέβαιος.
persevering: P. and V. λιπαρής (Plato), Ar. γλίσχρος.
ceaseless: P. ἄπαυστος; see incessant.