UNBELIEF IN THE "_MONUMENTUM ÆRE PERENNIUS._"--An actual drawback which accompanies the cessation of metaphysical views lies in the fact that the individual looks upon his short span of life too exclusively and receives no stronger incentives to build durable institutions intended to last for centuries,--he himself wishes to pluck the fruit from the tree which he plants, and therefore he no longer plants those trees which require regular care for centuries, and which are destined to afford shade to a long series of generations. For metaphysical views furnish the belief that in them the last conclusive foundation has been given, upon which henceforth all the future of mankind is compelled to settle down and establish itself; the individual furthers his salvation, when, for instance, he founds a church or convent, he thinks it will be reckoned to him and recompensed to him in the eternal life of the soul, it is work for the soul's eternal salvation. Can science also arouse such faith in its results? As a matter of fact, it needs doubt and distrust as its most faithful auxiliaries; nevertheless in the course of time, the sum of inviolable truths--those, namely, which have weathered all the storms of scepticism, and all destructive analysis--may have become so great (in the regimen of health, for instance), that one may determine to found thereupon "eternal" works. For the present the _contrast_ between our excited ephemeral existence and the long-winded repose of metaphysical ages still operates too strongly, because the two ages still stand too closely together; the individual man himself now goes through too many inward and outward developments for him to venture to arrange his own lifetime permanently, and once and for all. An entirely modern man, for instance, who is going to build himself a house, has a feeling as if he were going to immure himself alive in a mausoleum. 23.