Air is one of the four classical elements, and in the Aristotelian scheme of qualities it is hot and wet, light and mobile, rising above earth and water toward fire. As an element it stands for the mind, thought, speech and communication, for the intangible and the moving, breath and wind, the medium of sound and of the spoken word. The tradition assigns the three air signs, Gemini, Libra and Aquarius, to it, read as intellectual, social and oriented toward ideas and relationships. In humoral medicine air corresponds to blood and the sanguine temperament, warm and moist, sociable and optimistic.
In Western ceremonial magic air is placed in the east, the quarter of the rising sun and of dawn, associated with the ritual dagger or sword and with the faculty of intellect and analysis. Its attribution to the tarot suit of Swords is part of the Golden Dawn scheme of 1888. Throughout, air carries a symbolism of intellect, communication, freedom and the swift-moving, the element least bound to place and most identified with the life of the mind.
Sources The Presocratic PhilosophersG. S. Kirk, J. E. Raven and M. Schofield with The Golden Dawn: The Original Account of the Teachings, Rites, and Ceremonies of the Hermetic Order of the Golden Dawn, 6th editionIsrael Regardie