Opinion: An Army of OneBrent Nosworthy, in his book on Napoleonic-era battle tactics, With Musket, Cannon and Sword (Da Capo Press, 1996), points out that the development of increasingly sophisticated battle tactics rather paralleled the changes in European society at large. The commanding general in the Age of Reason held tightly the reins on the battlefield, with authority not to be delegated, except perhaps to a specialist such as a general of cavalry or artillery. A commander's lieutenant generals had almost no control over how their forces maneuvered and fought above the mechanical. This was practical as well as philosophical: Linear systems demanded that an army remain in lockstep. However, in the more egalitarian armies of Revolutionary France, the societal changes that made it conceivable for a commander in chief to delegate real authority to subordinate commanders enabled real tactical maneuvers on the battlefield - maneuvers that earlier thinkers had imagined and described but that could not be implemented in rigid contemporary systems.
One aspect of battle tactics during the transition from linear to so-called "impulse" systems of warfare was their intention to manage casualties. As columns of soldiers - formations first of maneuver, then of waiting, and ultimately of attack - got closer to the enemy guns, their densely packed ranks and files were more vulnerable to musket and especially cannon fire than soldiers in a line formation. In order to preserve a particular unit for when it was needed, it was sometimes necessary for it to deploy into line in the face of destructive fire so a given cannon ball would hit fewer men. Certainly, it was impossible to allow the men to take cover or lie down as individuals, as this would have a negative effect on unit integrity and even army cohesion (although sometimes isolated formations were allowed to lie down, if the rest of the army couldn't see them). It is worth noting that "ducking" was a derogatory term used to describe soldiers who flinched and bobbed their heads under fire as a sign of lack of discipline and low morale. These days, ducking is generally perceived as a sign of wisdom and good reflexes.
Military thinkers and commanders had an almost mathematical understanding of how many casualties a given unit could sustain under a given volume of fire over a given period of time. Various formations might be assumed in order to reduce casualties in the face of specific battlefield threats, such as cavalry or artillery, but only if this was not seen to have a disruptive effect on the army as a whole. There seems to have been little thought about how the Mrs. Sullivans of their day would bear news of the loss of their sons, or of how children would feel when they learned that Daddy wasn't coming home. Even fast-forwarding well into the modern era, notions of acceptable casualties exchanged for a certain result are commonplace.
As societies the world over come to value the individual, military systems have been evolving to follow suit. In Western-oriented armed forces, casualty management is not good enough: The goal of many current battlefield tactics and supporting technologies is casualty avoidance. The evolution of intelligence, surveillance, and reconnaissance; battlefield networks; stand-off, precision fires; and electronic warfare are all examples of how modern militaries exploit the skill and value the life of each individual warfighter. Every friendly casualty is viewed as a failure on some level. Some see this as a weakness. I see it as a strength, one that is entirely consistent with the relationship between a society and its military.
It must be frustrating - and maybe quietly terrifying - to face an enemy who expends money rather than lives to kill you.