How did Aristotle and the Stoics tie together happiness and knowledge?

Before I answer, let me just lay out where I'm coming from. First of all, I don't believe that this question can be answered too definitively because it is based on an interpretation of very old texts most of which I have only read in translation. The "Aristotelian", "Stoic", and "Epicurean" schools, which are based on the following texts. Aristotle discusses happiness in his "Nichomachean Ethics," to understand which it is necessary to read his "Physics," to understand which it is necessary to read his "On Logos" and "On the Soul." The ''Stoic" school is based on the thoughts of three men from early A.D. Greece and Rome, in the time of the Antonines. Their thoughts are contained in Epectitus' Discourses, Marcus Aurelius' Meditations, and Seneca's Epistles and other writings. The Epicurean school has no surviving direct texts but a few doubtful fragments of a work by one of Epicurus' followers. Our knowledge of it comes from satirical representations in Plato's dialogues, and later interpreters of Epicurus' writings. There is one latin treatise, however, that claims to be a faithful summary of Epicurus' thoughts (a claim always to be mistrusted): On the Nature of Things, by a roman "poet" called Lucretius. Since I have not read Seneca or Aurelius, and since I absolutely hate lucretius, I do not trust myself to give a faithful representation of the Stoics or Epicureans, but I think I can be of some help in understanding Aristotle.

Aristotle concluded, according to the precepts of his theory of language and knowledge, that happiness was something that was done. It was a mindful, present activity of the soul in accordance which Excellence and virtue. Accordingly, he laid out different kinds of happy dispositions that pursued pleasure, honor, and knowledge, whose hapiness would be compounded by the enjoyment of friendship. Differently disposed sould would have complementary friends who were similarly disposed, since he understood friendship to be the habitation or activity of one soul in two bodies. He ultimately concludes that activity of the soul in pursuit of Excellent and virtuous knowledge is the highest form of happiness, because it is naturally the kind of activity which our weak constitutions can carry on for the longest continuous time as well as being an activity which is greatly magnified by friendship through dialectic conversation. Thus, for Aristotle, happiness is the pursuit of knowledge, preferably through friendly, dialectic conversation.

As I said above, the comparison I'm about to make between Aristotle and the Stoics and Epicurean view on the relationship between knowledge and happiness is not entirely qualified or fair, but I will try to give some answer. Both Epictetus and Lucretius are very pre-occupied with death. Their views on happiness have more to do with death than on knowledge and friendship. Epictetus, being a slave for most of his life, views death as an equalizing fact of human life establishing its insignificance. Knowledge and constant meditation upon our death allows us to accept the insignificance of our own suffering and therefore live without suffering. Happiness, for him, therefore, seemed to me to be not suffering and not taking one's self too seriously, which is made possible by an appreciation of our own death and thus the insignificance of our lives. Similarly, Epicureanism, as it is represented by Lucretius, emphasizes the facts of our death and takes a "life is too short" kind of approach. He compounds this pre-occupation with a kind of crass "atomic theoretical" understanding of nature that interprets even our being alive as a product of pure chance. Thus, he concludes, since we are here by chance and will be gone any moment, that we should pursue pleasure without limiting the pleasure-seeking of our fellows. Hence the "Epicurean" life of pleasure.

Given all of this, from my point of view, the Stoics and Epicurean differ from Aristotle insofar as they view our life in relation to death. Whereas Aristotle views our life as given, and inherently valuable to the extent that we make it so (and even says in Book 10 of the Ethics that human beings should and can be immortal), the Stoics and Epicureans view are lives as necessarily shaped by death, and therefore to be lived as responses to a right knowledge of death. Thus, for them, knowledge and life are instruments and reactions, whereas Aristotle views morality, happiness and knowledge as inherently justified by the structure of our being as it is known from our desires and activities.