6. (It is generally agreed that) all calamities, sufferings, griefs
and similar evils are aggravated in proportion to their duration. If
then, in all these cases, evil be increased with time, why should not
the same circumstance obtain in the contrary case? Why should happiness
also not be increased?[56] Referring to griefs and sufferings, it might
reasonably be said that they are increased by duration. When, for
example, sickness is prolonged, and becomes a habitual condition, the
body suffers more and more profoundly as time goes on. If, however,
evil ever remain at the same degree, it does not grow worse, and
there is no need of complaining but of the present. Consideration of
the past evil amounts to considering the traces left by evil, the
morbid disposition whose intensity is increased by time, because its
seriousness is proportionate to its duration. In this case it is not
the length of time, but the aggravation of the evil which adds to
the misfortune. But the new degree (of intensity) does not subsist
simultaneously with the old, and it is unreasonable to predicate
an increase as summation of what is no more to what now is. On the
contrary, it is the fixed characteristic of happiness to have a fixed
term, to remain ever the same. Here also the only increase possibly
due to duration of time depends on the relation between an increase
in virtue and one in happiness; and the element to be reckoned with
here is not the number of years of happiness, but the degree of virtue
finally acquired.