For it is the province of virtue to use in a becoming manner the goods which are conformable to nature; but of prosperity to impart the use of them. And the former, indeed, imparts deliberate choice and right reason; but the latter, energies and actions. For to wish what is beautiful in conduct and to endure things of a dreadful nature, is the proper business of virtue. But it is the work of prosperity to render deliberate choice successful, and to cause actions to arrive at the [desired] end. For the general conquers in conjunction with virtue and good fortune. The pilot sails well in conjunction with art and prosperous winds. The eye sees well in conjunction with acuteness of vision[59] and light. And the life of man becomes most excellent through virtue itself, and prosperity. FROM HIPPARCHUS, IN HIS TREATISE ON TRANQUILLITY. Since men live but for a very short period, if their life is compared with the whole of time, they will make a most beautiful journey as it were, if they pass through life with tranquillity. This however they will possess in the most eminent degree, if they accurately and scientifically know themselves, viz. if they know that they are mortal and of a fleshly nature, and that they have a body which is corruptible and can be easily injured, and which is exposed to every thing most grievous and severe, even to their latest breath. And in the first place, let us direct our attention to those things which happen to the body; and these are pleurisy, inflammation of the lungs, phrensy, gout, stranguary, dysentery, lethargy, epilepsy, putrid ulcers, and ten thousand other diseases. But the diseases which happen to the soul are much greater and more dire than these. For all the iniquitous, evil, illegal, and impious conduct in the life of man, originates from the passions of the soul. For through preternatural immoderate desires many have become subject to unrestrained impulses, and have not refrained from the most unholy pleasures, arising from being connected with daughters or even mothers. Many also have been induced to destroy their fathers, and their own offspring. But what occasion is there to be prolix in narrating externally impending evils, such as excessive rain, drought, violent heat and cold; so that frequently from the anomalous state of the air, pestilence and famine are produced, and all-various calamities, and whole cities become desolate? Since therefore many such-like calamities are impendent, we should neither be elevated by the possession of corporeal goods, which may rapidly be consumed by the incursions of a small fever, nor with what are conceived to be prosperous external circumstances, which frequently in their own nature perish more rapidly than they accede. For all these are uncertain and unstable, and are found to have their existence in many and various