Military strategy in the 19th century was still viewed as one of a trivium of "arts" or "sciences" that govern the conduct of warfare; the others being tactics, the execution of plans and maneuvering of forces in battle, and logistics, the maintenance of an army. The view had prevailed since the Roman times, and the borderline between strategy and tactics at this time was blurred, and sometimes categorization of a decision is a matter of almost personal opinion. Carnot, during the French Revolutionary Wars thought it simply involved concentration of troops.