Final answer:
Pythagoras, a 6th-century BCE Greek philosopher, created a brotherhood with four degrees, known for expertise in mathematics, music, and astronomy, and distinct societal customs.
Step-by-step explanation:
The Greek philosopher who developed a brotherhood containing four degrees was Pythagoras. Known primarily for his contributions to mathematics and philosophy, Pythagoras founded a rational yet mystical sect known as the Pythagoreans around the 6th century BCE. The Pythagoreans were recognized for their extensive knowledge in various subjects, including mathematics, music, and astronomy, as well as for their unique societal practices. Pythagoras wrote nothing himself, so our understanding comes from his disciples' records. Nonetheless, the brotherhood he established was said to be divided into different degrees of initiation and learning, signifying the levels of understanding and knowledge his followers attained.