The moments when the mind turns to the past and risks a synthesis of what endures from all that it has done and lived are always fruitful: it is often here that apparently useless works prove their worth; it is also here that routine futilities are exposed in a patent way. Then it is possible to notice that there is little that is truly resistant to the effects of time, and thus to reinvigorate priorities that may have been neglected. But beyond that: it is when the mood weakens and hope is shattered that such an exercise proves most useful—and the mind sees in it something that justifies persistence.