Legalism is not a Choice, It is a Necessity
When a warring state is in chaos the only way to control it is to rule by striking fear in the hearts of your people through the distribution of harsh punishments. After your people are afraid, you can then gain their cooperation by giving generous rewards to those who follow your rule. By treating your people with this disregard, you are maintaining the main objective of legalism, looking out for the welfare of the state.
I am a philosopher and advisor to the King of Zhao. He is worried that his country will rebel against him due to years of economic hardship. He has come to me because he would like to know how to stop this rebellion before it begins. I explained to the king that in harsh times, one must first use tyrannical power to force people into submission and cooperation. After cooperation is obtained, giving generous rewards for righteousness will ensure further cooperation. The result of this legalist approach is that, "Severe punishments would restrain violations, while generous rewards would encourage what was beneficial to the strength and well-being of the state(Sources,191)."
I explained to his greatness that the legalist approach to maintaining the well being of his state is to put the interest of the state first and foremost among human concern. In other words, the common people that live in your empire are to be treated only as pawns in a large game of chess. Not only do legalists need to treat humans this way but they also need to take count of many other things in their empire and consider them before making a strategic move. A strong state will always know the exact numbers of everything useful in the state. This includes knowing how many humans there are and what they are capable of, as well as an account for the capabilities of animals, weapons, and food in the empire. All these things need to be taken into account and used as tool...