Then his companion might say, with perfect justice, "I will do this additional work for you; but if I do it, you must promise to do as much for me at another time. I will count how many hours I spend on your ground, and you shall give me a written promise to work for the same number of hours on mine, whenever I need your help, and you are able to give it." Suppose the disabled man's sickness to continue, and that under various circumstances, for several years, requiring the help of the other, he on each occasion gave a written pledge to work, as soon as he was able, at his companion's orders, for the same number of hours which the other had given up to him. What will the positions of the two men be when the invalid is able to resume work? Considered as a "Polis," or state, they will be poorer than they would have been otherwise: poorer by the withdrawal of what the sick man's labour would have produced in the interval. His friend may perhaps have toiled with an energy quickened by the enlarged need, but in the end his own land and property must have suffered by the withdrawal of so much of his time and thought from them; and the united property of the two men will be certainly less than it would have been if both had remained in health and activity. But the relations in which they stand to each other are also widely altered. The sick man has not only pledged his labour for some years, but will probably have exhausted his own share of the accumulated stores, and will be in consequence for some time dependent on the other for food, which he can only "pay" or reward him for by yet more deeply pledging his own labour. Supposing the written promises to be held entirely valid (among civilized nations their validity is secured by legal measures[33]), the person who had hitherto worked for both might now, if he chose, rest altogether, and pass his time in idleness, not only forcing his companion to redeem all the engagements he had already entered into, but exacting from him pledges for further labour, to an arbitrary amount, for what food he had to advance to him.