(See Hudibras, Pt. iii. c. 3.)
He that fights and runs away May live to fight another day; But he that is in battle slain Can never rise to fight again.
Demosthenes, being reproached for running away from Philip of Macedon, at Chæronea, replied, “A man that runs away may fight again ('Aner o pheugon kai palin machesetai).” (See Aulus Gellius, xvii. 21.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894