Pythagoras, a pre-Socratic philosopher, regarded numbers not just as mathematical concepts but as fundamental to understanding the structure of reality.
Key points:
1. Pythagoras viewed numbers as the underlying formal or relational structure of the universe.
- Numbers are not physical or material entities but define relationships and patterns in the cosmos.
- For example, musical harmony is explained through numerical ratios, such as the intervals of octaves and fifths.
2. Incorrect options:
- (A) As a material entity: Numbers are not considered material or tangible in Pythagoras's philosophy.
- (C) As a principle of change and permanence: While Pythagoras acknowledged cosmic order, he did not define numbers as principles of change or permanence.
- (D) As abstract entities existing in the world: Numbers were more than abstract entities; they were the structural principles of reality.
Thus, the correct answer is (B) As constituting the formal or relational structure.