Final answer:
The philosophy that focused on self-discipline, duty, and rational living was Stoicism, which became popular among Roman aristocrats for its alignment with Roman values and its emphasis on the four virtues of courage, justice, temperance, and wisdom.
Step-by-step explanation:
The philosophy that emphasized self-discipline and the fulfillment of one's duties, which taught tolerance and forgiveness, is Stoicism. Stoicism taught individuals to maintain a rational outlook on life, accepting fate, and avoiding strong emotional reactions such as fear and anger. It advocated for living in harmony with nature and believing in the power of human reason. The Stoic philosophy aligned well with Roman values of strength, service, and rational self-control, and became particularly influential among the Roman aristocrats.
Stoicism, as a philosophy, put forward the idea that leading a virtuous life in accordance with nature and its laws is of paramount importance. The Stoics believed in four core virtues: courage, justice, temperance, and wisdom. They held that inner freedom could be achieved through rational self-control and constant striving to maintain a state of moral and emotional restraint. As such, Stoicism provided guidance for individuals in how to live a life of integrity and purpose, irrespective of one's external circumstances.