History of the Peloponnesian War

And so they advanced; the Syracusans, to fight for their country, and their own personal safety at present, and freedom in future;— the Athenians, on the side of their opponents, to fight for another people's land, that they might win it as their own; and to avoid weakening their own by defeat;—the Argives and the independent allies, to join them in securing the objects they had come for, and by means of victory to look again on the country that was already theirs;—while the subject allies showed a ready zeal, most of all, for their immediate safety, which was hopeless unless they conquered; then, as a secondary consideration, for the chance of serving on easier terms, in consequence of having assisted to reduce a fresh country under the Athenian dominion.

When they had come to close combat, they withstood each other's attacks for a long time. And there happened to come on at once both thunder, and lightning, and heavy rain: so that to those who were fighting for the first time, and had had very little acquaintance with war, even this helped to increase their fear; while to the more experienced party these occurrences appeared to be produced simply by the season of the year, but the fact of their opponents not being defeated caused far greater alarm.

But when the Argives had first driven in the left wing of the Syracusans, and after them the Athenians had repulsed those opposed to them, the rest of the Syracusan army was now also broken and put to flight.