hings without a
guardian of perfect age.

Of the second, which is the height of our life, the time is variously
taken by many. But leaving that which philosophers and medical men
write concerning it, and returning to the proper argument, we may say
that, in most men in whom one can and ought to be guided by natural
judgment, that age lasts for twenty years. And the reason which leads
me to this conclusion is, that the height or supreme point of our arc
or bow is in the thirty-fifth year; just so much as this age has of
ascent, so much it ought to have of descent; and this ascent passes
into descent, as it were, at the point, the centre, where one would
hold the bow in the hand, at which place a slight flexion may be
discerned. We are of opinion, then, that Youth is completed in the
forty-fifth year.

And as Adolescence is in the twenty-five years which proceed mounting
upwards to Youth: so the descent, that is, Old Age, is an equal amount
of time which succeeds to Youth; and thus Old Age terminates in the
seventieth year.

But because Adolescence does not begin at the beginning of
life--taking it in the way which has been said--but about eight months
from birth; and because our life strives to ascend, and curbs itself
in the descent; because the natural heat is lessened and can do
little, and the moist humour is increased, not in quantity, but in
quality, so that it is less able to evaporate and be consumed; it
happens that beyond Old Age there remains of our life an amount,
perhaps, of about ten years, a little more or a little less; and this
time of life is termed Extreme Old Age, or Senility. Wherefore we know
of Plato (of whom one may well say that he was a son of Nature, both
because of his perfection and because of his countenance, which caused
Socrates to love him when first he saw him), that he lived eighty and
one years, according to the testimony of Tullius in that book On Old
Age. And I believe that if Christ had not been crucified, and if He
might have lived the length of time which His life according to nature
could have passed over, at eighty and one years He would have been
transformed from the mortal body into the eternal.

Truly, as has been said above, these ages may be longer or shorter
according to our complexion or temper and our constitution or
composition; but, as they are, it seems to me that I observe this
proportion in all men, as has been said, that is to say, that in such
men the ages m