Natural elements
Natural elements refer to various conceptualizations of the fundamental components or forces that constitute the natural world, spanning ancient philosophies, cultural traditions, scientific understandings, and modern applications. In Western classical philosophy, these are commonly known as the four elements—earth, water, air, and fire—posited by ancient Greek thinkers in the 5th century BCE as the primary substances composing all matter.[1] This theory, first articulated by Empedocles and later refined by Aristotle, who assigned each element specific qualities and natural motions, provided a foundational framework for cosmology that influenced Western thought for millennia.[2][3] Other traditions offer different systems, such as the five elements (wood, fire, earth, metal, water) in East Asian philosophy, while modern science interprets natural elements through chemical compositions found in the environment and physical phenomena like forces and states of matter.[4] The classical elements also shaped medieval disciplines like alchemy, medicine (via the four humors), and astrology, though they were largely supplanted by chemistry in the 17th and 18th centuries, notably through Antoine Lavoisier's work. Today, they persist as metaphors in literature, psychology, and environmental philosophy.[5][6]Classical philosophy
Ancient Greek origins
The concept of the four classical elements—earth, water, air, and fire—originated in ancient Greek philosophy during the pre-Socratic period, with Empedocles of Acragas (c. 495–435 BCE) introducing them as the fundamental "roots" (rhizomata) of all matter around 450 BCE.[1] Empedocles proposed these roots as eternal, unchangeable, and indestructible building blocks, combined and separated by the opposing cosmic forces of Love (philia), which unites them, and Strife (neikos), which divides them, to form the diverse phenomena of the universe.[7] This theory marked a shift from earlier monistic views, such as those of Thales or Anaximenes, by positing multiple eternal principles rather than a single originating substance, thereby providing a pluralistic framework for understanding generation and corruption in the natural world.[1] Aristotle (384–322 BCE) systematized and expanded Empedocles' ideas in works such as On Generation and Corruption and On the Heavens, defining the four elements by their primary qualities: hot or cold, and wet or dry, which determine their essential natures and behaviors within the sublunary sphere—the changeable region below the moon encompassing the terrestrial world. Earth is cold and dry, water is cold and wet, air is hot and wet, and fire is hot and dry; these qualities not only characterize the elements but also explain their natural motions, with heavy elements (earth and water) tending downward toward the center of the universe and light elements (air and fire) tending upward.[8] In Aristotle's cosmology, the elements constitute all mutable bodies in the sublunary realm, undergoing qualitative changes to produce mixtures and compounds, while the supralunary sphere above the moon consists of the unchanging fifth element, aether. Plato (c. 428–348 BCE), in his dialogue Timaeus, adopted the four elements and associated each with one of the regular polyhedra: fire with the tetrahedron, air with the octahedron, water with the icosahedron, and earth with the cube. He proposed that these geometric forms could transform into one another by rearrangement of their triangular faces, providing a mathematical foundation for elemental change, with the dodecahedron reserved for the cosmos itself.[9] The Hippocratic medical tradition, developed in the 5th–4th centuries BCE, integrated these elemental concepts into theories of health and disease, associating the four bodily humors—blood, phlegm, yellow bile, and black bile—with the elements and their qualities to explain physiological balance.[10] Blood corresponds to air (hot and wet), phlegm to water (cold and wet), yellow bile to fire (hot and dry), and black bile to earth (cold and dry); imbalances among these humors, influenced by diet, environment, and seasons, were believed to cause illness, with treatments aimed at restoring equilibrium through evacuation or regimen.[11] This humoral theory, rooted in the Hippocratic Corpus, underscored the elements' role in both cosmic and human order, linking macrocosmic principles to microcosmic bodily functions.[5] Aristotle further elaborated on elemental intertransformations, positing that elements could convert into one another by altering a single primary quality, preserving the underlying prime matter while allowing for natural change without true generation or destruction.[2] For instance, fire (hot and dry) transforms into air (hot and wet) by replacing dryness with wetness, air into water (cold and wet) by replacing hotness with coldness, water into earth (cold and dry) by replacing wetness with dryness, and earth back to fire by replacing coldness with hotness, forming a continuous cycle.[12] This schema can be illustrated as follows:| Element | Primary Qualities | Transformation Example |
|---|---|---|
| Fire | Hot, Dry | To Air: Add wetness (remove dry) |
| Air | Hot, Wet | To Water: Add cold (remove hot) |
| Water | Cold, Wet | To Earth: Add dry (remove wet) |
| Earth | Cold, Dry | To Fire: Add hot (remove cold) |
Medieval and Renaissance developments
In the 13th century, Thomas Aquinas synthesized Aristotelian philosophy with Christian theology, incorporating the four classical elements—earth, water, air, and fire—into a cosmological framework where they served as the basic constituents of the sublunary world, created by God as part of the ordered natural hierarchy.[14] This adaptation reconciled pagan naturalism with divine creation, positing that the elements' qualities (hot, cold, wet, dry) explained terrestrial change while celestial realms consisted of the purer fifth element, aether, aligning Aristotelian hylomorphism with the Christian view of matter as informed by God's eternal forms.[14] Aquinas' Summa Theologica thus established these elements as tools for understanding God's rational design, influencing medieval scholasticism by framing natural philosophy as a pathway to theological truth. By the 16th century, alchemical traditions built upon this foundation, with Paracelsus introducing quintessence, or ether, as a fifth element embodying the pure, life-giving essence beyond the four terrestrial ones, often linked to astral influences and medicinal extraction.[15] He derived the tria prima—salt (fixity and body), sulfur (combustibility and soul), and mercury (volatility and spirit)—from combinations of the classical elements, applying them practically in iatrochemistry to treat diseases through elixirs and metallurgical processes that balanced humoral imbalances.[16] These principles shifted alchemy toward empirical healing, viewing the elements not merely as static building blocks but as dynamic forces manipulable for therapeutic ends, marking a transition from speculative philosophy to proto-scientific experimentation. The Renaissance saw a revival of elemental ideas through humanism and cosmology, as exemplified by Giordano Bruno, who envisioned an infinite universe of countless worlds where elemental cycles—transformations among earth, water, air, fire, and aether—occurred homogeneously without Aristotelian boundaries between sublunary and celestial realms.[17] This pantheistic view, articulated in works like De l'infinito, universo e mondi (1584), portrayed elements as infinite atoms forming diverse, animate systems, challenging geocentric orthodoxy and emphasizing perpetual natural flux.[17] Concurrently, elemental symbolism permeated Renaissance art, with Leonardo da Vinci's notebooks documenting studies of elemental interactions, such as fire's action on air akin to air on water or water on earth, to explore natural motions and proportions in painting, anatomy, and mechanics.[18] A pivotal cultural artifact of this era, the Hypnerotomachia Poliphili (ca. 1499), an allegorical dream-vision printed by Aldus Manutius, wove elemental motifs into its narrative of love and quest, depicting landscapes and figures symbolizing the harmony and strife of earth, water, air, and fire as metaphors for the soul's ascent.[19]Cultural variations
Eastern traditions
In Eastern traditions, the concept of natural elements manifests through distinct philosophical systems that emphasize dynamic interdependence and cyclical processes, differing from Western models by focusing on relational balance rather than inherent qualities such as hot or cold.[20] The Chinese wu xing, or five phases, represents a foundational framework originating in the Warring States period (475–221 BCE), where it emerged among scholars at the Jixia Academy in the state of Qi.[20] This system comprises wood (mu), fire (huo), earth (tu), metal (jin), and water (shui), conceptualized not as static substances but as transformative processes influencing all aspects of existence.[21] The doctrine was systematized by the philosopher Zou Yan (c. 305–240 BCE), who integrated it into cosmological explanations of natural and historical cycles, as recorded in Sima Qian's Records of the Historian.[20] Central to wu xing are two interlocking cycles that govern elemental interactions: the generating (sheng) cycle, where wood produces fire, fire produces earth, earth produces metal, metal produces water, and water produces wood, symbolizing nourishment and growth; and the overcoming (ke) cycle, where wood parts earth, earth absorbs water, water extinguishes fire, fire melts metal, and metal chops wood, representing control and restraint to maintain equilibrium.[21] These cycles underpin a cosmology of universal harmony, linking elements to seasons, directions, planets, and dynastic successions—for instance, the Zhou dynasty was associated with fire due to its red ritual colors, signaling heavenly mandate.[21] In traditional Chinese medicine, as outlined in the Huangdi Neijing (c. 1st century BCE), the elements correspond to visceral organs and meridians: wood to the liver and gallbladder, fire to the heart and small intestine, earth to the spleen and stomach, metal to the lungs and large intestine, and water to the kidneys and bladder, with imbalances in sheng or ke cycles informing diagnosis and acupuncture treatments.[20] Similarly, in feng shui, practitioners arrange environments to harmonize elemental flows, such as positioning water features to "control" excessive fire energies for spatial well-being.[20] Parallel to wu xing, Indian philosophy articulates the mahabhuta, or five great elements—earth (prithvi), water (ap or jala), fire (tejas or agni), air (vayu), and space (akasha)—as the foundational constituents of the material universe, first referenced in Vedic texts around 1500 BCE.[22] Hymns in the Rigveda, such as those to Agni (fire) in 1.1 and Vayu (air), personify these elements as deities integral to cosmic order, while the Nāsadīya Sūkta (10.129) posits water as a primordial source of creation.[22] The Upanishads, particularly the Taittiriyopanishad, expand this into a sequential evolution from the subtle to the gross: space arises first from the ātman, followed by air, fire, water, and earth, with the Chāndogyopanishad describing their intermixing through pancikarana, a process where each element incorporates portions of the others to form composite matter.[22] In Samkhya philosophy, as detailed in the Sāṃkhyakārikā, the mahabhuta derive from tanmatras—subtle essences of sound (for space), touch (for air), form (for fire), taste (for water), and smell (for earth)—which evolve from prakriti (primordial nature) via ahamkara (ego-sense), ultimately manifesting gross physical forms and the human body while underscoring the interdependence of all phenomena.[23] A unifying principle across these Eastern systems is the emphasis on elemental interdependence through cycles of production and regulation, as seen in wu xing's sheng-ke dynamics or the mahabhuta's pancikarana blending, fostering a worldview of holistic balance without fixed hierarchies of quality.[20] For example, just as wood fuels fire in generation while water douses it in overcoming, the mahabhuta interpenetrate such that space pervades all others, ensuring no element dominates in isolation.[22] This relational approach permeates ethics, medicine, and cosmology, promoting harmony as the path to understanding natural order.[21]Indigenous and other global perspectives
In Indigenous traditions across the Americas and Africa, natural elements are often conceptualized not as inert substances but as integral parts of a living cosmos, intertwined with spiritual practices and human existence. These perspectives emphasize relational balance and reciprocity, where elements serve as mediators between the physical world and the sacred. Native American cultures, such as the Lakota and Navajo, incorporate the four elements into the medicine wheel, a symbolic circle representing interconnectedness and harmony. Associations with directions vary by tradition, each evoking cycles of life, seasons, and personal growth.[24][25] Among the Hopi, elements manifest as living spirits through kachina rituals, where over 400 kachina beings personify natural forces like rain, clouds, and plants to ensure fertility and communal well-being, teaching balance with the environment via dances and carvings.[26] African cosmologies similarly animate elements through divine intermediaries. In Yoruba tradition, orishas embody elemental powers; for instance, Shango, the orisha of thunder and lightning, wields fire as a force of justice and destruction, invoked in rituals with drums and red offerings to channel his volatile energy.[27] The Dogon of Mali view water as the primordial element in their creation myths, where the supreme being Amma forms the universe from a cosmic egg immersed in watery chaos, with the Nommo—amphibious water spirits—guiding life's emergence and maintaining cosmic order.[28] Mesoamerican systems extend elemental frameworks to include celestial dimensions. Aztec cosmology recognizes earth, water, air, and fire as foundational forces, supplemented by stars or quintessence as a fifth ethereal principle linking the terrestrial and divine realms in cyclical world ages.[29] In Maya narratives from the Popol Vuh, creation unfolds through sky, earth, and water, with the ceiba tree as the world axis that separates primordial waters from the heavens, rooting in the underworld while branches reach the stars to sustain all life.[30] A defining feature of these perspectives is animism, wherein elements are regarded as sentient entities capable of agency, emotion, and interaction with humans, fostering ethical responsibilities to maintain equilibrium rather than dominance over nature.[31]Scientific interpretations
Chemical elements in nature
Naturally occurring chemical elements are those found on Earth without human intervention, totaling 94 distinct elements from hydrogen (atomic number 1) to plutonium (94), in contrast to the approximately 24 synthetic elements produced solely in laboratories.[32] Primordial elements, such as hydrogen, helium, and trace lithium, originated from Big Bang nucleosynthesis shortly after the universe's formation, while heavier elements formed through subsequent astrophysical processes.[33] These natural elements include over 250 stable isotopes across 80 elements that do not undergo radioactive decay, with the remaining elements featuring long-lived radioactive isotopes.[34] The abundance of these elements varies significantly across Earth's layers, reflecting their formation histories and geochemical behaviors. In the crust, oxygen and silicon dominate, comprising the bulk of silicate minerals that form the planet's surface.[35] The atmosphere, by contrast, is primarily composed of nitrogen and oxygen, essential for life and weather patterns.[36] Iron plays a pivotal role in the core, making up about 85% of its mass and enabling the dynamo effect that generates Earth's protective magnetic field.[37]| Rank | Element | Symbol | Abundance in Earth's Crust (by mass %) |
|---|---|---|---|
| 1 | Oxygen | O | 46.1 |
| 2 | Silicon | Si | 28.2 |
| 3 | Aluminum | Al | 8.2 |
| 4 | Iron | Fe | 5.6 |
| 5 | Calcium | Ca | 4.2 |
| 6 | Sodium | Na | 2.4 |
| 7 | Magnesium | Mg | 2.3 |
| 8 | Potassium | K | 2.1 |
| 9 | Titanium | Ti | 0.57 |
| 10 | Hydrogen | H | 0.14 |