"Not just that every day more of our life is used up and less and less of it is left, but this too: if we live longer, can we be sure our mind will still be up to understanding the world — to the contemplation that aims at divine and human knowledge? If our mind starts to wander, we’ll still go on breathing, go on eating, imagining things, feeling urges and so on. But getting the most out of ourselves, calculating where our duty lies, analyzing what we hear and see, deciding whether it’s time to call it quits — all the things you need a healthy mind for . . . all those are gone. So we need to hurry. Not just because we move daily closer to death but also because our understanding — our grasp of the world—may be gone before we get there."