Aristotle Four Elements: Air

In On the Heavens (350 BC), Aristotle defines "element" in general:

An element, we take it, is a body into which other bodies may be analysed, present in them potentially or in actuality (which of these, is still disputable), and not itself divisible into bodies different in form. That, or something like it, is what all men in every case mean by element. — Aristotle, On the Heavens, Book III, Chapter III

In his On Generation and Corruption, Aristotle related each of the four elements to two of the four sensible 'qualities':

• Fire is both hot and dry.
• Air is both hot and wet (for air is like vapor, ἀτμὶς).
• Water is both cold and wet.
• Earth is both cold and dry.