160. Since the lowest constituents of nature which form the elemental earths are lifeless, and they are not changeable and variable in accordance with states of affections and thoughts as in the spiritual world, but are inalterable and fixed, therefore we find in nature intervals of space and extents of space. These constituents are as described because creation terminated in them and in its resting ceased. Consequently it is apparent that intervals of space are properties of nature; and because intervals of space in nature are not appearances of space in accordance with states of life as in the spiritual world, they can also be called lifeless.