Every art and every inquiry, and similarly every action and pursuit, is thought to aim at some good; and for this reason the good has rightly been declared to be that at which all things aim." - 1094a (Nicomachean Book I, Ch. 1)
To Aristotle, Happiness is the result of doing the right thing, and the right thing is the action that results from Virtue.
Therefore, every good action derives from another good action, and all goodness can be traced back to the Highest Good. This exponent of good has three characteristics: It's desirable for its own sake; it's not desirable for the sake of another good; all other goods are desirable for its sake. Roughly, one could go as far as to say something like "goodness is as goodness does - in and of itself, never against".
The highest Good resolves in eudaemonia. This word is usually translated as Happiness, but it can also mean Well-Being, as well as Flourishing. Man can achieve happiness by following his own design: "The function of Man is activity of Soul in accordance to reason, or at least not without reason". That is, one needs to understand what one is good at, what sets one apart from others, and by consistently doing it, fulfillment can be achieved. According to this philosopher, there are only two things for the man to do, which are reasoning and following reasoning, or perhaps feeling and transmitting, or maybe reflecting and acting.
"The Virtuous person sees the truth in each case, being as it were a standard and measure of them". Aristotle does not think that merely doing good actions is enough. One needs to nurture Virtue, and it is trough Virtue that true goodness arises spontaneously. ...