Apophthegmata Laconica

Plutarch

Plutarch. Moralia, Vol. III. Babbitt, Frank Cole, translator. Cambridge, MA: Harvard University Press; London: William Heinemann Ltd., 1931 (printing).

When someone asked why they visited disgrace upon those among them who lost their shields, but did not do the same thing to those who lost their helmets or their breastplates, he said, Because these they put on for their own sake, but the shield for the common good of the whole line.