The theory admittedly breaks down when we come to the relations of matter and space.

The relational theory of space is an admission that we cannot know space without matter or matter without space.

But the seclusion of both from time is still jealously guarded.

The relations between portions of matter in space are accidental facts owing to the absence of any coherent account of how space springs from matter or how matter springs from space.

Also what we really observe in nature, its colours and its sounds and its touches are secondary qualities; in other words, they are not in nature at all but are accidental products of the relations between nature and mind.
The explanation of nature which I urge as an alternative ideal to this accidental view of nature, is that nothing in nature could be what it is except as an ingredient in nature as it is.