In evaluating Aristotle's arguments for his claim that happiness (eudaimonia) is the goal of human life, I believe it is important to recognise the true problem at hand, which can be seen to be, does Aristotle succeed arguing that happiness (eudaimonia) is the goal of human life? I believe that overall Aristotle does not succeed in arguing this point but that he does provide some very sound arguments in defending some of his opinions.
Aristotle believed that "all human activities aim at some good" and for this reason, he initially defines the good as "that at which all things aim". For example, medicine seeks health just like learning seeks knowledge. Both health and knowledge are thought to be good but at the same time they are also seen to be ends. Aristotle viewed ends as being either activities or the products that are produced by the activities e.g. the activity of flute playing is an end while a house is also seen to be an end as it is the product of the activity of house-building. But some ends are clearly subordinate to others. Aristotle used the example of Bridle making, which falls under the art of riding, along with every other military action, which all fall under the art of strategy. Clearly there is a master art for which all others are subordinate to, and so, "it is for the sake of the former that the latter are pursued". In other words, there is an end which man desires purely for its own sake with everything else being desired for the sake of this. This final end, Aristotle called the Chief Good. Aristotle thought that if we knew what this Chief Good was, then this would have a great influence on life. He believed that if anything, the Chief Good would be associated mainly with political science as he saw this as being the master art. He argued that since "politics ordains which of the sciences should be studied in a state" and "legislates as to what we are to do and what we are to abstain from, the end of this science must include those of the others, so that this must be the good for man".
The good for man, Aristotle suggests, is generally agreed to be happiness. But as we all know, different men view happiness in different ways. Some view it as pleasure, others see it as wealth and as Aristotle believed, those involved in the master art that is political science, see it as honour. But he felt that this was too superficial, as honour depends more on those who bestow it rather than those receiving it. He goes on to argue that maybe virtue rather than honour is the end of the political life since men only wish to be honoured to prove their merit and at the same time only wish to be honoured by other men on the grounds of the virtue of those men. But again Aristotle is not satisfied with this, as virtue to him is compatible with being asleep, yet no one would call happy a man who lives like this.
In order to discover the Chief good of man, Aristotle decided that it was necessary to consider the telos (end or goal) of man. By doing this he concluded that "if there is only one and final end, this will be what we are seeking and if there is more than one, the most final of these will be what we are seeking". And so he decided, it could be only one such thing, happiness, for it is only ever chosen for the sake of itself and never for the sake of something else. But on the other hand, things such as "honour, pleasure, reason and every virtue" are chosen both for themselves yet also and more importantly for the sake of being happy. He argues that by us "judging through them", we believe we will be happy.
With happiness now considered to be the Chief good, Aristotle begins to look at it from different points of view. He argues that happiness is self-sufficient and defines it as "that which when isolated makes life desirable and lacking in nothing". He views it as "something final and self-sufficient"...