Your Productive Life is Only as Long as You Retain Your Mental Faculties

We ught to consider not only that our life is daily wasting away and a smaller part of it is left, but another thing also must be taken into the account, that if a man should live longer, it is quite uncertain whether the understanding will still continue sufficient for the comprehension of things, and retain the power of contemplation which strives to acquire the knowledge of the divine and the human. For if he shall begin to fall into dotage, perspiration and nutrition and imagination and appetite, and whatever else there is of the kind, will not fail; but the power of making use of ourselves, and filling up the measure of our duty, and clearly separating all appearances, and considering whether a man should now depart from life, and whatever else of the kind absolutely requires a disciplined reason, all this is already extinguished. We must make haste then, not only because we are daily nearer to death, but also because the conception of things and the understanding of them cease first.