Fire is one of the four classical elements of the Greek tradition, set out by Empedocles in the fifth century BCE as one of the four roots of all things and systematised by Aristotle, who paired each element with two of the qualities hot, cold, wet and dry: fire is hot and dry. In that physics fire is the lightest element after none, rising upward, and it is associated with heat, energy, transformation and the active principle. The tradition assigns the three fire signs of the zodiac, Aries, Leo and Sagittarius, to it, and in the four-temperament medicine descending from Hippocrates and Galen fire corresponds to yellow bile and the choleric temperament, quick to anger and to action.
In Western esotericism fire is one of the four elements invoked at the cardinal points of ritual, conventionally placed in the south and linked to the will and to spirit. Its later attribution to the suit of Wands in the tarot is a Golden Dawn addition of 1888, not part of the ancient scheme. Fire's symbolism throughout is of energy, passion, purification and the transformative.
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