The quality of passage in durations is a particular exhibition in nature of a quality which extends beyond nature.

For example passage is a quality not only of nature, which is the thing known, but also of sense-awareness which is the procedure of knowing.

Durations have all the reality that nature has, though what that may be we need not now determine.

The measurableness of time is derivative from the properties of durations.

So also is the serial character of time.