Book First discusses the Chief Good, or the Highest End of all human endeavours. Every exercise of the human powers aims at some good; all the arts of life have their several ends--medicine, ship-building, generalship. But the ends of these special arts are all subordinate to some higher end; which end is the chief good, and the subject of the highest art of all, the Political; for as Politics aims at the welfare of the state, or aggregate of individuals, it is identical with and comprehends the welfare of the individual (Chaps. I., II.). As regards the _method_ of the science, the highest exactness is not attainable; the political art studies what is just, honourable, and good; and these are matters about which the utmost discrepancy of opinion prevails. From such premises, the conclusions which we draw can only be probabilities. The man of experience and cultivation will expect nothing more. Youths, who are inexperienced in the concerns of life, and given to follow their impulses, can hardly appreciate our reasoning, and will derive no benefit from it: but reasonable men will find the knowledge highly profitable (III.). Resuming the main question--What is the highest practical good--the aim of the all-comprehending political science?--we find an agreement among men as to the name _happiness_ [Greek: eudaimonia]; but great differences as to the nature of the thing. The many regard it as made up of the tangible elements--pleasures, wealth, or honour; while individuals vary in their estimate according to each man's state for the time being; the sick placing it in health, the poor in wealth, the consciously ignorant in knowledge. On the other hand, certain philosophers [in allusion to Plato] set up an absolute good,--an Idea of the Good, apart from all the particulars, yet imparting to each its property of being good (IV.). Referring to men's lives (as a clue to their notions of the good), we find three prominent varieties; the life of pleasure or sensuality,--the political life, aspiring to honour,--and the contemplative life. The first is the life of the brutes, although countenanced by men high in power. The second is too precarious, as depending on others, and is besides only a means to an end--namely, our consciousness of our own merits; for the ambitious man seeks to be honoured for his virtue and by good judges--thus showing that he too regards virtue as the superior good. Yet neither will virtue satisfy all the conditions. The virtuous man may slumber or pass his life in inactivity, or may experience the maximum of calamity; and such a man cannot be regarded as happy. The money-lender is still less entitled, for he is an unnatural character; and money is obviously good as a means. So that there remains only the life of contemplation; respecting which more presently (V.).