Anxiety is a narrowing.

The Daoist classic Liezi, in its "Tianrui" chapter, records this tale. In the state of Qi there lived a man who worried day and night: "If the sky collapses and the earth caves in, where shall I flee?" His worry ran so deep that he could neither eat nor sleep. A neighbor, troubled for him, came and explained: "The sky is only accumulated vapor. Vapor is everywhere. You breathe and move within that vapor — how could it collapse?" Then the man of Qi worried again: "But what of the sun, the moon, and the stars? What if they fall?" The neighbor said: "Sun, moon, and stars are only lights within that vapor. Even if they fell, they could do no harm." The man asked again: "And if the earth caves in?" The neighbor answered: "The earth is only clods of soil. It fills every direction; there is no gap for it to cave into." At last the man of Qi rejoiced and was at ease, and the neighbor was at ease too. But a sage named Zhanglu zi heard the story, laughed, and said: "He knows neither that the sky will not fall, nor that it could. Whether it falls or not is not for us to know. To live well while we are here — that is wisdom." When Liezi heard this, he laughed in turn and said: "The one who believes it will fall is a fool, the one who argues it will not is a fool, and the one who says he cannot know is a fool too. All three are right, and all three are wrong."

The root of the English anxiety is the Latin verb angere. Its basic meaning was "to choke, to suffocate, to narrow." In the medical literature of the Roman era, angere literally denoted difficulty in breathing — the feeling of a tight chest where the air will not pass. From this verb several nouns were derived: angor (constriction, oppression), anxietas (lasting oppression), angustia (a narrow passage). What is striking is the family of English words sprung from the same Proto-Indo-European root, *angh- ("to constrict") — anger, anguish, angina (constriction of the heart), and the German Angst. Rage, suffering, the pain of the heart, existential dread — all are different faces of the single root meaning "narrowing." The Romans understood anxiety not as "a thought in the head" but as a physical event, a passage of the body closing up. Cicero drew distinctions: aegritudo (grief) concerned the past, metus (fear) concerned a specific object, and anxietas was an oppression that persisted without any object. Nearly two thousand years later, this classification is repeated almost verbatim in Sigmund Freud's 1926 work Inhibitions, Symptoms and Anxiety. Freud defined anxiety (Angst) as "objektlose Furcht" — fear without an object. The English anxiety was borrowed directly from Latin in the 1520s. Until the seventeenth century it was used mainly as a medical term; from the nineteenth century onward it became a central concept in philosophy, literature, and psychology. Søren Kierkegaard's 1844 work The Concept of Anxiety was the decisive turning point.