Xenophon,
Anabasis — Book 4, Chapter 8
“ Accordingly Xenophon said: "I am not for advancing in line, but advise to form companies by columns. To begin with, the line," he urged, "would be scattered and thrown into disorder at once; for we shall find the mountain full of inequalities, it will be pathless here and easy to traverse there. The mere fact of first having formed in line, and then seeing the line thrown into disorder, must exercise a disheartening effect. Again, if we advance several deep, the enemy will none the less overlap us, and turn their superfluous numbers to account as best they like ”
