Again, Socrates being asked whether courage is something teachable or natural, “I think,” said he, “just as a body is by nature more resistant to pain than another body, so, too, one soul to another soul comes by nature stronger with regard to misfortune; for I see that there is too much difference among those who are brought up by the same law and under the same customs.
On the other hand, however, I do believe that every nature gets much improvement in daring by learning and studying. For clearly the Scythians and Thracians do not wish to fight against Lacedaemonians with shields and spears, nor do the Lacedaemonians wish to conflict with the Thracians using small shields and javelins, neither with the Scythians using bows.
Whence it follows that clearly in matters one wishes to become notable, these one should both learn and study”.
Bibliography: Xenophon, Memorabilia (126.96.36.199 to 188.8.131.52)
Translation: George Kotsalis