For fire burns whoever touches it, but it also gives light and warmth, and is an instrument of art to all those who know how to use it.[502] Consider also in the case of the enemy, if he is in other respects injurious and intractable, he somehow or other gives us a handle to make use of him by, and so is serviceable. And many things are unpleasant and detestable and antagonistic to those to whom they happen, but you must have noticed that some use even illnesses as a period of rest for the body, and others by excessive toil have strengthened and trained their bodily vigour, and some have made exile and the loss of money a passage to leisure and philosophy, as did Diogenes and Crates. And Zeno, when he heard of the wreck of the ship which contained all his property, said, "Thou hast done well, Fortune, to confine me to my threadbare cloak."[503] For as those animals that have the strongest and healthiest stomachs eat and digest serpents and scorpions, and some even feed on stones and shells, which they convert into nourishment by the strength and heat of their stomachs, while fastidious people out of health almost vomit if offered bread and wine, so foolish people spoil even their friendships, while the wise know how to turn to account even their enmities. Sec. III. In the first place then it seems to me that what is most injurious in enmity may become most useful to those that pay attention to it? To what do I refer? Why, to the way in which your enemy ever wide awake pries into all your affairs, and analyzes your whole life, trying to get a handle against you somewhere, able not only to look through a tree, like Lynceus,[504] or through stones and shells, but through your friend and domestic and every intimate acquaintance, as far as possible detecting your doings, and digging and ferreting into your designs. For our friends are ill and often die without our knowing anything about it through our delay and carelessness, but we almost pry into even the dreams of our enemies; and our enemy knows even more than we do ourselves of our diseases and debts and differences with our wives.[505] But they pay most attention to our faults and hunt them out: and as vultures follow the scent of putrid carcases, and cannot perceive sound and wholesome ones, so the diseases and vices and crimes of life attract the enemy, and on these those that hate us pounce, these they attack and tear to pieces. Is not this an advantage to us? Certainly it is. For it teaches us to live warily and be on our guard, and neither to do or say anything carelessly or without circumspection, but ever to be vigilant by careful mode of living that we give no handle to an enemy. For the cautiousness that thus represses the passions and follows reason implants a care and determination to live well and without reproach. For as those states that have been sobered by wars with their neighbours and continual campaigns love the blessings of order and peace, so those