Lesson 2.8: Pneuma

Glossary

Philosophical Concepts

Eudaimonia – Often translated as “flourishing” or “well-being,” it refers to a life lived in accordance with nature and reason. For the Stoics, this means developing virtue and becoming indifferent to things beyond one’s control.

Virtue (Arete) – The only true good, defined as the perfection of reason in the soul. For Stoics, virtue includes wisdom, courage, justice, and temperance.

Kataleptic Impressions – Perceptions that are clear, distinct, and irresistible to the rational mind—i.e., impressions that can be assented to with confidence. The Stoics believed these could be the basis of knowledge.

Assent – The mental act of agreeing with or accepting an impression. Stoic ethics hinges on our ability to withhold assent from misleading or irrational impressions.

Impressions (Phantasiai) – Appearances or perceptions that strike the mind. The Stoic path to virtue involves carefully evaluating these impressions before giving assent.

Pneuma – The active, animating principle of the universe; often translated as “breath” or “spirit.” Pneuma is what organizes and sustains the cosmos and pervades all living things.

Logos – Divine rationality or order that governs the universe. Human beings, as rational animals, are capable of aligning their lives with this cosmic Logos.

Oikeiōsis – The Stoic concept of "appropriation" or "familiarization," beginning with self-preservation and gradually expanding outward into care for others. This forms the basis of social and ethical life.

Apatheia – Freedom from irrational passions. Not emotionlessness, but rather the ideal state of inner calm and clarity that comes from being unmoved by things outside our control.

Living According to Nature – The central Stoic principle of aligning one's life with both human nature (rationality) and the nature of the cosmos.

Determinism – The Stoic belief that everything happens according to a divine rational plan. This is not fatalism, since humans still have agency through their responses and judgments.

Logic, Physics, and Ethics

Logic – The Stoics viewed logic as a necessary tool for developing virtue. It includes grammar, dialectic (reasoned dialogue), and epistemology (study of knowledge).

Physics – A naturalistic, divine account of the universe. Everything is composed of matter structured by pneuma (divine breath), and events follow causal necessity.

Ethics – The culmination of Stoic thought. The good life consists of living virtuously by responding to impressions rationally and maintaining inner tranquility despite external circumstances.

People & Schools

Zeno of Citium – Founder of Stoicism; taught that virtue is the only good and that one should live in agreement with nature.

Chrysippus – One of the most influential Stoic philosophers; systematized Stoic logic and was famous for his rigorous and paradox-filled arguments.

Cleanthes – Student of Zeno who composed the Hymn to Zeus, emphasizing the religious and pantheistic elements of Stoic thought.

Epictetus – A former slave turned philosopher who taught that we must focus only on what is within our power. His ideas are recorded in the Discourses and Enchiridion.

Seneca – Roman Stoic and statesman; emphasized practical ethics and self-examination. His letters contain reflections on grief, anger, friendship, and the shortness of life.

Marcus Aurelius – Roman emperor and Stoic practitioner. His Meditations are a journal of personal philosophical reflections in the face of imperial duties and hardship.

Epicureans – Often contrasted with the Stoics; they believed that pleasure (particularly mental tranquility) was the highest good, while Stoics believed in virtue as the only good.

Skeptics (Academic and Pyrrhonian) – Challenged Stoic epistemology by arguing that certain knowledge was impossible or that no beliefs should be held with confidence.

Key Ethical Ideas & Practices

Emotions as Judgments – For Stoics, emotions are not passive feelings but value-laden judgments. For example, anger is the mistaken belief that one has been unjustly harmed.

Withholding Assent – The core Stoic practice of suspending agreement with impressions that have not been rationally examined. This is how one achieves apatheia.

The Dichotomy of Control – One of the most famous Stoic teachings: some things are within our control (our thoughts, actions, and judgments), and some things are not (external events, other people, the past). Wisdom lies in knowing the difference.

The View from Above – A meditative exercise in which one imagines their place within the vastness of the cosmos, encouraging humility and detachment.

Daily Reflection – Many Stoics, like Seneca and Marcus Aurelius, engaged in daily journaling or reflection to assess their ethical progress and prepare for the day.

Living in Harmony with the Whole – Stoics urge us to understand our place in the universe and to embrace our roles and relationships with others as parts of a greater whole.

Words You Might Not Know

Pneuma – A Greek word meaning “breath” or “spirit,” used by Stoics to describe the animating force of the cosmos.

Assent – Philosophically, to give mental approval to a perception or belief; for Stoics, this is a voluntary act.

Apatheia – Not apathy, but the state of rational emotional tranquility.

Logos – A Greek term meaning “reason” or “word,” central to Stoic theology and cosmology.

Determinism – The belief that all events follow a necessary order of cause and effect.

Kataleptic – Capable of grasping truth with certainty; used by Stoics to describe trustworthy impressions.

Oikeiōsis – The process of natural moral development, from self-care to concern for others.

Impression (Phantasia) – The raw data of experience, which the Stoic sage must evaluate before assenting to.

The Sage – The ideal Stoic figure who has perfect self-control, lives in accordance with nature, and is indifferent to external goods and harms.