This cultivation of excellence is what Aristotle defines as happiness. There is a pleasure that derives from the achievement of living well or living ethically. The ultimate goal of the Nicomachean Ethics is then the establishment of what is good and how it is obtained teleologically, or purpose-driven. As Aristotle proposed, "every art and investigationseems to aim at some good," and that this end was happiness. (Bk. I, Ch. 1).
In order to answer what role pleasure plays in a happy life it is necessary to differentiate and define what happiness and pleasure respectively mean first. Happiness and pleasure are not synonymous terms, though pleasure can be obtained through living in accordance to the happy life. In the Nicomachean Ethics, the word that was translated to "happiness" is derived from the Greek word "eudaimonia" that carries with it a connotation meaning excellence and high value. Happiness should not be mistaken, as it is defined in contemporary and popular usage as a relative state characterized by the amount of pleasure received from something or liking to something. Instead happiness is instead living a virtuous life, or as Aristotle wrote, happiness is "the activity of the soul in accordance to virtue." (Bk. I, Ch. VII). Requisite in this is the explanation regarding how the soul can be engaged in accordance to virtue and what virtue itself means. Virtue did not pertain to being highly moralistic as it does today, but rather it pertained to its degree of excellence and value. Virtue was translated from the Greek word "arte" that directly relates to the means excellence. Therefore, something was virtuous if it achieved its goal or end well. For example, a computer was virtuous if it processed information well, and performed the myriad of other tasks with proficiency and skill. For a person, this meant that they were virtuous if they lived and achieved happiness. The arte of man is his ability to reason and the more well or excellently he reasoned, the more virtuous he or she was. Living rationally then is living excellently and doing well, and reason is the activity of the soul, or as Aristotle defined as "the exercise of the soul's faculties in conformity with virtue in a complete life." (Bk. I, Ch VII).
Pleasure on the other hand holds a different meaning in the Nicomachean Ethics. Pleasure is the positive feelings one obtains through the actions, as opposed to the aim of the actions themselves. For example, if an individual decides to exercise vigorously daily, they may improve their physical appearance to others as a result. Any compliments by others would make the individual feel good, and that good sensation is pleasure. While the aim of exercising might be something else, that is better health and more energy, and the compliments made by others are secondary. The virtuous act of exercise and physical fitness is to get into better health while the pleasurable act would be the compliments towards a more attractive physical appearance. Aristotle would not consider the intended purpose of receiving compliments because of exercise to of excellent virtue, but rather of hedonistic pleasure. Pleasure should not be the end goal, but part of