Final answer:
The Qin dynasty used Legalism to unify China through strict laws, harsh punishments, and centralized control.
Step-by-step explanation:
The Qin dynasty used Legalism to unify China by implementing policies that focused on strict laws, harsh punishments, and centralized control. Legalist policies such as the standardization of laws and punishments, the centralization of power under the emperor, and the promotion of a strong military all helped the Qin gain and maintain power.
Learn more about Legalism in the Qin dynasty