XXV. What a small portion of vast and infinite eternity it is, that is allowed unto every one of us, and how soon it vanisheth into the general age of the world: of the common substance, and of the common soul also what a small portion is allotted unto us: and in what a little clod of the whole earth (as it were) it is that thou doest crawl. After thou shalt rightly have considered these things with thyself; fancy not anything else in the world any more to be of any weight and moment but this, to do that only which thine own nature doth require; and to conform thyself to that which the common nature doth afford.