In its most general sense, work means activity, and in that sense it may be said that everything works in nature; everything is in motion; everywhere we see effort, energy, unfolding of forces. Take but the animals: the bird works to build its nest; the spider to weave its web; the bee to make her honey; the beaver to construct its lodges; the dog to catch the game; the cat to catch mice. We find among animals workmen of all sorts: masons, architects, tailors, hunters, travelers; even politicians and artists, as if they had been destined to set us examples in all kinds of work and activity. "In the morning," says Marcus Aurelius, "when thou hast trouble in getting up, say to thyself: I awake to do the work of a man: why, then, should I grieve for having to do things for which I am born, for which I was sent into the world? Was I born to remain warmly in bed under my cover?--But it is so pleasant.--Wert thou born for pleasure, then? Was it not for action, for work? Seest thou not the plants, the sparrows, the ants, the spiders, the bees, filling each their functions, and contributing according to their capacity to the harmony of the world? And shouldst thou refuse to attend thy functions as man? Shouldst thou not follow the biddings of nature?"[103] The ancients distinguished two kinds of work: noble and independent work, namely, the arts, the sciences, war and politics; and servile or mercenary work imposed by necessity. The latter they deemed below the dignity of man; manual labor, properly so called, useful work, distinct from gymnastics and military exercises, they considered as belonging exclusively to slaves. It is to this Aristotle referred when he said: "There are men who have but just the necessary amount of reason to understand the reason of others: it is they whose only work is useful manual labor. It is obvious that such men cannot belong to themselves; they belong necessarily to others; they are slaves by nature." Aristotle believed, moreover, that nature herself had made the distinction between the freeman and the slave: "Nature," he said, "made the bodies of the freemen different from those of the slaves; she gave to the latter the necessary vigor for the heavy work of society, and made the former unable to bend their erect natures to such rude labors."[104] It is not necessary to have lived to this present time to find these errors refuted. Before Aristotle, Socrates had already understood the dignity of labor, even of the productive labor insuring a livelihood; he had seen that work in itself was not servile, as the following charming account related by Xenophon, well proves: "Socrates, observing, on one occasion, Aristarchus looking gloomily, 'You seem,' said he, 'Aristarchus, to be taking something to heart; but you ought to impart the cause of your uneasiness to your friends; for, perhaps, we may by some means lighten it.'