Complex sentence: The concept of space is considered to be of fundamental importance to an understanding of the physical universe, although disagreement continues between philosophers over whether it is itself an entity, a relationship between entities, or part of a conceptual framework.
Split into simpler sentences: The concept of space is considered to be of fundamental importance to an understanding of the physical universe. However, disagreement continues between philosophers over whether it is itself an entity, a relationship between entities, or part of a conceptual framework.