Nicomachean Ethics is arguably Aristotle's best known work on ethics. The work consists of ten books which originally were his lecture notes at the Lyceum that were later edited by his son, Nicomachus. Throughout the work, Aristotle spends the majority of his books providing his account of what he believes to be human beings' ultimate goal, one that is self-sufficient and absolute final. He also shows his belief regarding virtues and the method of upholding them. Aristotle argues that the ultimate end in life is eudaimonia, or happiness; in order to achieve this goal, one must act in accordance with virtue, the "golden mean" in between excess and deficiency.
Aristotle argues that the ultimate goal that we all seek is happiness. He claims that every human activity is a stepping stone towards a goal that human beings consider "good". This goal's goodness does not necessarily have to be considered as good by others; it must be perceived as good for the person who commits that action in order to reach a favorable end. Aristotle considers ends to be either activities or the products that come from activities. He also suggests that some ends are clearly subordinate to higher ones, forming a hierarchy where smaller goals serve as stepping stones to higher goals. At the highest point of this hierarchy is the most important end, or the ultimate end. Thus, for a goal to become ultimate, it must be achievable by man, "always be desirable in itself and never for the sake of something else." (Aristotle book. 1, chapter. 7) Aristotle calls this end the "Supreme Good" (Aristotle bk. 1, chapter. 2) which, as he suggests, is widely considered to be happiness.
Different people give different views on what happiness is and how to attain it. Aristotle looks at happiness as something "that which when isolated makes life desirable and lacking nothing" he also views it as "something final and self-sufficient, and is the end of action.