| Professor Barbour [1] | Professor Smolin [2] |
| The change of things is time. | Time is the most real aspect of our perception of the world. |
| Time is simply a complex of rules that govern the change. | Non-causal children time is the most real aspect of our perception of the world. |
| Time is inferred from things. | Space is emergent and approximate. |
| Time is in the instant. | Laws of nature evolve in time. |