Two great philosophical rivals emerged in opposition to Epicureans, namely the Stoics and the Skeptics. The debates among these Hellenistic schools (especially between the Epicureans and the Stoics) spurred Epicureans to develop some of their doctrines in much greater detail, notably their epistemology and some of their ethical theories, especially their theories concerning friendship and virtue. There were also occasional revivals of Platonism (the Lyceum seems to have become absorbed in the natural sciences and went into eclipse). Some pluralism started to creep into Epicurean doctrines (notably over the nature of friendship), but for the most part Epicurean beliefs remained amazingly consistent under the pressure of philosophical disputations, while Stoicism and particularly Platonism seem to have undergone steady changes in their doctrines.
Epicurus's philosophy combines a physics based on an atomistic materialism with a rational hedonistic ethics that emphasizes moderation of desires and cultivation of friendships. His world-view is an optimistic one that stresses that philosophy can liberate one from fears of death and the supernatural, and can teach us how to find happiness in almost any situation. His practical insights into human psychology, as well as his science-friendly world-view, gives Epicureanism great contemporary signficance as well as a venerable role in the intellectual development of Western Civilization.
In contrast to the Stoics , Epicureans showed little interest in participating in the politics of the day, since doing so leads to trouble. He instead advocated seclusion. This principle is epitomised by the phrase lathe biōsas ( λάθε βιώσας ), meaning "live in obscurity", "get through life without drawing attention to yourself", ., live without pursuing glory or wealth or power, but anonymously, enjoying little things like food, the company of friends, etc. Plutarch elaborated on this theme in his essay Is the Saying "Live in Obscurity" Right? ( Εἰ καλῶς εἴρηται τὸ λάθε βιώσας , An recte dictum sit latenter esse vivendum ) 1128c; cf. Flavius Philostratus , Vita Apollonii .