Fire has been an important part of all cultures and religions from pre-history to modern day and was vital to the development of civilization. It has been regarded in many different contexts throughout history, but especially as a metaphysical constant of the world.
Fire is one of the four classical elements in ancient Greek philosophy and science. It was commonly associated with the qualities of energy, assertiveness, and passion. In one Greek myth, Prometheus stole fire from the gods to protect the otherwise helpless humans, but was punished for this charity.
Fire was one of many archai proposed by the Pre-socratics, most of whom sought to reduce the cosmos, or its creation, to a single substance. Heraclitus (c. 535 BCE – c. 475 BCE) considered fire to be the most fundamental of all elements. He believed fire gave rise to the other three elements: "All things are an interchange for fire, and fire for all things, just like goods for gold and gold for goods." He had a reputation for obscure philosophical principles and for speaking in riddles. He described how fire gave rise to the other elements as the: "upward-downward path", (ὁδὸς ἄνω κάτω), a "hidden harmony" or series of transformations he called the "turnings of fire", (πυρὸς τροπαὶ), first into sea, and half that sea into earth, and half that earth into rarefied air. This is a concept that anticipates both the four classical elements of Empedocles and Aristotle's transmutation of the four elements into one another.
This world, which is the same for all, no one of gods or men has made. But it always was and will be: an ever-living fire, with measures of it kindling, and measures going out.