Stoicism arose in Athens around 300 BCE when Zeno of Citium began teaching philosophy in a public colonnade called the Stoa Poikile, or "Painted Porch," from which the school takes its name. Zeno organized his teaching into three interconnected branches: Logic, which governs how we think; Physics, which examines the nature of the cosmos; and Ethics, which addresses how we should live. These branches were never isolated: Stoics held that understanding the rational order of the universe, what they called logos, directly informs how to act well. Logos refers both to the divine reason that pervades and governs all things and to the structure of rational thought in which human beings share. Stoics are sometimes described as pantheists because they identified the rational principle with nature itself, treating God and the cosmos as one.
At the heart of practical Stoicism lies the dichotomy of control, perhaps best articulated by Epictetus in his Enchiridion. Some things are within our power—our judgments, choices, and intentions—while others are not: external events, other people's actions, the past, and the future. This distinction does not counsel passivity but redirects energy toward what we can actually influence. The Stoic goal of life is eudaimonia, a Greek term meaning "good spirit" or flourishing, attained through living virtuously and in accordance with nature. To live according to nature means two complementary things: aligning our lives with our own rational human nature, and harmonizing ourselves with the rational order of the cosmos, sometimes called the kosmos.
Because nature is itself organized by logos, the wise person learns to cooperate with this order rather than resist it. Stoics spoke of events occurring by fate or necessity, while our freedom lies in how we respond. They pictured the cosmos cycling through periods of conflagration (ekpyrosis) and renewal, an ordered, beautiful whole animated by what they called providence—a rational principle whose purposes may not always be discernible but which can be trusted. The Stoic approach to time is similarly grounded: the past is done, the future uncertain, and life itself occurs only in the present moment, sometimes likened to a flowing river in which we stand. Across this ordered world runs a sense of interconnection, an idea expressed by the term sympatheia, the recognition that all things in the universe are related. The view of the afterlife is generally absorption back into the cosmic logos rather than personal immortality.