Alexias's experiences throughout The Last of the Wine turn him from a boy into a man. Initially a callow youth, Alexias quickly matures due to a number of crises, both personal and political, that are unceremoniously thrust upon him.
For instance, Alexias shows great courage and compassion by refusing to accede to his father's order that if Alexias's stepmother gives birth to a daughter Alexias will grab the baby from her and see to it that the child dies from exposure. This was quite a common occurrence in those days. However immoral such an instruction may appear, Alexias would've been expected to obey his father to the letter in this as in all things.
From then on, Alexias develops his emotional maturity even in the midst of war. He joins up to fight the Spartans along with his lover and bosom friend Lysis. Despite this concession to traditional Athenian values, Alexias never loses his capacity for critical thought, which has been honed by his spending time in the company of the great philosopher Socrates.
So when Alexias's commanding officer, another former pupil of Socrates, the unreliable and reckless Alcibiades, leads his troops to disaster, we can be sure that Alexias knows what's up. He's a brave and loyal soldier, not an unthinking automaton.