[W]hen night came on, the Macedonians and the barbarian crowd suddenly took fright in one of those mysterious… — Thucydides

Ignorance produces rashness, reflection timidity

By day certainly the combatants have a clearer notion, though even then by no means of all that takes place, no one knowing much of anything that does not does not go on in his own immediate neighborhood; but in a night engagement (and this was the only one that occurred between great armies during the war) how could anyone know anything for certain?

The dead lay unburied, and each man as he recognized a friend among them shuddered with grief and horror; while the living whom they were leaving behind, wounded or sick, were to the living far more shocking than the dead, and more to be pitied than those who had perished.