Fire. Fire is one of the four classical elements in ancient Greek philosophy and science. It is a powerful and destructive force and has been a recurring theme in art throughout history. Fire has been depicted in various ways, often symbolizing passion, transformation, or destruction. In ancient cave paintings, it was depicted as a source of warmth and light, essential for survival. In religious art, fire has been used to symbolize divine power, purification, or hell. In more modern art, fire can represent social and political unrest, industrialization, or personal struggles. It is 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 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, a hidden harmony  or series of transformations he called the turnings of fire, 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. Heraclitus regarded the soul as being a mixture of fire and water, with fire being the more noble part and water the ignoble aspect. He believed the goal of the soul is to be rid of water and become pure fire: the dry soul is the best and it is worldly pleasures that make the soul moist. He was known as the weeping philosopher and died of hydropsy, a swelling due to abnormal accumulation of fluid beneath the skin. However, Empedocles of Acragas, is best known for having selected all elements as his archai and by the time of Plato, the four Empedoclian elements were well established. In the Timaeus, Plato's major cosmological dialogue, the Platonic solid he associated with fire was the tetrahedron which is formed from four triangles and contains the least volume with the greatest surface area. This also makes fire the element with the smallest number of sides, and Plato regarded it as appropriate for the heat of fire, which he felt is sharp and stabbing.