When one gains happiness, he gains also stability and rest. Hence we see that animals that live for a short time take a short time in arriving at maturity. That is the perfect good of happiness, which is absolutely free from admixture of evil, as that is perfect whiteness, which is absolutely unmingled with black. There is no man living who is not at times disturbed by inordinate passions, who does not at times overstep the mean in which virtue consists, or fall short of it, who is not in some things deceived, or ignorant of what he wishes to know, or driven to weak surmises on points where he would like absolute certainty.
Man naturally shrinks from death, and is sad at the thought of it.
Yet man must die, and therefore cannot be perfectly happy while here he lives. But it is impossible in this life to do any act continually. The more a thing is desired and loved, the greater grief and sadness does its loss bring. Such happiness therefore must always have a natural pendent of sadness. Now it is demonstrable that the aforesaid answer is not to the undoing of the arguments above alleged.