The Stoics are especially known for teaching that "virtue is the only good" for human beings, and that external things—such as health, wealth, and pleasure—are not good or bad in themselves, but have value as "material for virtue to act upon". Alongside Aristotelian ethics, the Stoic tradition forms one of the major founding approaches to Western virtue ethics. The Stoics also held that certain destructive emotions resulted from errors of judgment, and they believed people should aim to maintain a will (called prohairesis) that is "in accord with nature". Because of this, the Stoics presented their philosophy as the Word of God (lex divina), and they thought the best indication of an individual's philosophy was not what a person said, but how a person behaved. To live a good life, one had to understand the rules of the natural order since they taught everything was rooted in nature.
Many Stoics—such as Seneca and Epictetus—emphasized that because "virtue is sufficient for happiness", a sage would be emotionally resilient to misfortune. This belief is similar to the meaning of the phrase "stoic calm", though the phrase does not include the "radical ethical" Stoic views that only a sage can be considered truly free, and that all moral corruptions are equally vicious.
Stoicism flourished throughout the Roman and Greek world until the 3rd century AD, and among its adherents was Emperor Marcus Aurelius. It experienced a decline after Christianity became the state religion in the 4th century AD. Since then it has seen revivals, notably in the Renaissance (Neostoicism) and in the modern era (modern Stoicism).
Stoic comes from the Greek stōïkos, meaning "of the stoa ". This, in turn, refers to the Stoa Poikile, or "Painted Stoa," in Athens, where the influential Stoic Zeno of Citium taught. In laymen's terms stoicism is sometimes referred to as "suffering in silence", and the ethics associated with that.
The Stoics provided a unified account of the world, consisting of formal logic, monistic physics and naturalistic ethics. Of these, they emphasized ethics as the main focus of human knowledge, though their logical theories were of more interest for later philosophers.