Final answer:
The Pythagorean philosophers indeed rejected materialism, holding the belief that the essence of the universe is numerical, which aligns with the true statement in the student's question.
Step-by-step explanation:
The statement that Pythagorean philosophers rejected materialism and embraced the idea that everything is reduced to immaterial numbers is indeed true. Pythagoras and his followers, known as Pythagoreans, proposed that the foundation of reality is numerical in nature. They saw the world as constructed from numbers and believed that mathematical principles could explain occurrences in the natural world. This belief extended to viewing the soul as immortal, with reincarnation as a central doctrine, further reflecting their non-materialistic perspective. The Pythagoreans held that through rigorous reasoning and study of mathematics, one could come to understand the true essence of the universe.