Classical element
Classical elements typically refer to ancient concepts similar to the modern states of matter: earth (solid), water (liquid), air (gas) and fire (plasma). Classical elements are the simplest form of existence, of everything in existence. Many philosophies and worldviews believe in classical elements.
Historians trace the evolution of modern theory of chemical elements, chemical compounds, and chemical substance mixtures, to medieval and Greek models.
Many concepts once thought to be analogous, such as the Chinese Wu Xing, are now understood more figuratively.
Ancient
In classical thought, the four elements earth, water, air, and fire frequently occur; sometimes including a fifth element or quintessence (after "quint" meaning "fifth") called aether in ancient Greece and akasha in India. The concept of the five elements formed a basis of analysis in both Hinduism and Buddhism. In Hinduism, particularly in an esoteric context, the four states-of-matter describe matter, and a fifth element describes that which was beyond the material world. Similar lists existed in ancient China and Japan. In Buddhism the four great elements, to which two others are sometimes added, are not viewed as substances, but as categories of sensory experience.
