1. ‘Mathematically, time is no different from one more spatial dimension, but since humans interact with it in a quite different way, it is psychologically very different.’ William P. Thurston, ‘On Proof and Progress in Mathematics’, p. 5

This raises a question: what is different between our conception of time and our conception of space? Initially I thought that if we visualise a process through time, we can’t imagine it ‘all at once’ which would be possible if we conceived of the process as evolving through space. However, the idea of ‘all at once’ seems to implicity assume understanding of time, at least if we rephrase it as ‘all at the same time’. But possibly we could reduce it to the concept of unity, without referencing time.