However much pains may be taken to combine the soldier and the citizen in one and the same individual, whatever may be done to nationalize wars, never will it be possible to do away with the professionalism of the business; and if that cannot be done, then those who belong to it will always look upon themselves as a kind of guild, in the regulations, laws, and customs in which the "Spirit of War" finds its expression. It would be very wrong to look down upon this corporate spirit, or esprit de corps, which may and should exist more or less in every Army.
Carl von ClausewitzIn War, the young soldier is very apt to regard unusual fatigues as the consquence of faults, mistakes, and embarrassment in the conduct of the whole, and to become distressed and depondent as a consequence. This would not happen if he had been prepared for this beforehand by exercises in peace.
Carl von Clausewitz