αὐτὸν κέκρουκας τὸν βατῆρα τοῦ λόγου → you have struck the very threshold of the argument, you have struck the most important and chiefmost point
prognōsis: is, f., = πρόγνωσις.
I Foreknowledge, Isid. 12, 7, 19.—
II Esp., as med. t. t., prognosis, forecast, in disease, Cael. Aur. Tard. 4, 8, 112.