Final answer:
The Buddha's act of leaving his comfortable life to seek spiritual truth is known as renunciation. This led to the birth of Buddhism and its core principles, like the middle way, the Four Noble Truths, and the Eightfold Path.
Step-by-step explanation:
The act of Buddha leaving his home and family in search of spiritual truth is known as renunciation. Siddhartha Gautama, the prince who would become the Buddha, embarked on this radical departure from a life of luxury after recognizing the inevitability of aging, sickness, and death. This pivotal moment led to his quest for enlightenment and was a foundational event in the creation of Buddhism, which emphasizes the importance of personal responsibility and the pursuit of a moral life through the acceptance of the Four Noble Truths and adherence to the Eightfold Path. Furthermore, a key teaching is the middle way, a path of moderation away from the extremes of self-indulgence and self-mortification.