Classical element

The Greek classical elements are fire, air, water, and earth. They represent in Greek philosophy, science, and medicine the possible constituents of the cosmos.

Plato mentions them as of Pre-Socratic origin, a list created by the philosopher Empedocles.

Fire is both hot and dry.

Air is both hot and wet.

Water is both cold and wet.

Earth is both cold and dry.

One classic diagram (right) has two squares on top of each other, with the corners of one being the classical elements, and the corners of the other being the properties.

According to Galen, these elements were used by Hippocrates in describing the human body with an association with the four humours: phlegm[?] (water), yellow bile[?] (fire), black bile (earth), and blood (air).

Some cosmologies include a fifth element, aether.

The Pythagoreans added idea as the fifth element, and also used the initial letters of these five elements to name the outer angles of their pentagram.

In Chinese Taoism there is a similar system, which includes metal and wood but excludes air. Different things in nature are associated with the five types. For example, the five major planets were named after the elements: Venus is metal, Jupiter is wood, Mercury is water, Mars is fire and Saturn is earth. Also the Moon represents Yin, the Sun represents Yang. Yin and Yang and the five elements are recurring themes in the I Ching, which is strongly related to Chinese cosmology and astrology. See Chinese five elements.

Some South Asian traditions also include the air, earth, fire, water distinctions.

The modern scientific periodic table of the elements and the understanding of combustion (fire) can be considered successors to such early models.

If one associates the modern term 'Plasma' with fire, the other three elements correspond with the modern concept of 'states of matter', this is to say 'Solid' maps to Earth, 'Liquid' to Water and 'Gas' to Air.

See also

• The Fifth Element.
• Quintessence
• The four humours