When I consider the wonderful activity of the mind, so great a memory of what is past, and such a capacity of penetrating into the future: when I behold such a number of arts and sciences, and such a multitude of discoveries hence arising,--I believe and am firmly persuaded that a nature which contains so many things within itself cannot be mortal.
The best Armour of Old Age is a well spent life preceding it; a Life employed in the Pursuit of useful Knowledge, in honourable Actions and the Practice of Virtue; in which he who labours to improve himself from his Youth, will in Age reap the happiest Fruits of them; not only because these never leave a Man, not even in the extremest Old Age; but because a Conscience bearing Witness that our Life was well-spent, together with the Remembrance of past good Actions, yields an unspeakable Comfort to the Soul
Let art, then, imitate nature, find what she desires, and follow as she directs. For in invention nature is never last, education never first; rather the beginnings of things arise from natural talent, and ends are reached by discipline.
So it may well be believed that when I found him taking a complete holiday, with a vast supply of books at command, he had the air of indulging in a literary debauch, if the term may be applied to so honorable an occupation.