Air

The four Classical Elements were first proposed by the Greek philosopher Empedocles (c. 450 BCE). Prior to this, philosophers debated on what the root of all matter was, and held differing opinions on what this single material might be. Empedocles proposed that there were in fact four primordial materials: earth, air, fire, and water. This concept was developed by Plato and Aristotle, who elaborated on the sensible qualities of the elements. Later each element took on additional philosophical and metaphorical roles as organizing principles. For example, Galen described the human body as having four humors each relating to a Classical element. In Medieval Europe, these elements transitioned into the elemental system used by alchemists, which added the concept of three Primes, represented by mercury, salt, and sulphur.

The Scientific Revolution replaced the alchemical understanding of matter, but the Classical Elements still hold influence on a figurative level. Plants and planets that were assigned an elemental ruler in the past are still known by these correspondences today by esoteric practitioners to organize their understanding of their properties on a symbolic level.