Some scholars trace the origins of natural science as far back as pre-literate human societies, where understanding the natural world was necessary for survival. People observed and built up knowledge about the behaviour of animals and the usefulness of plants as food and medicine, which was passed down from generation to generation. These primitive understandings gave way to more formalized inquiry around 3500 to 3000 BC in the
Mesopotamian and
Ancient Egyptian cultures, which produced the first known written evidence of
natural philosophy, the precursor of natural science. While the writings show an interest in astronomy, mathematics, and other aspects of the physical world, the ultimate aim of inquiry about nature's workings was, in all cases, religious or mythological, not scientific. A tradition of scientific inquiry also emerged in
Ancient China, where
Taoist alchemists and philosophers experimented with elixirs to
extend life and cure ailments. They focused on the
yin and yang, or contrasting elements in nature; the yin was associated with femininity and coldness, while yang was associated with masculinity and warmth. The five phases – fire, earth, metal, wood, and water – described a cycle of transformations in nature. The water turned into wood, which turned into the fire when it burned. The ashes left by fire were earth. Using these principles, Chinese philosophers and doctors explored human anatomy, characterizing organs as predominantly yin or yang, and understood the relationship between the pulse, the heart, and the flow of blood in the body centuries before it became accepted in the West. Little evidence survives of how
Ancient Indian cultures around the
Indus River understood nature, but some of their perspectives may be reflected in the
Vedas, a set of sacred
Hindu texts. They reveal a conception of the universe as ever-expanding and constantly being recycled and reformed. Surgeons in the
Ayurvedic tradition saw health and illness as a combination of three humours:
wind,
bile and
phlegm. A healthy life resulted from a balance among these humours. In Ayurvedic thought, the body consisted of five elements: earth, water, fire, wind, and space. Ayurvedic surgeons performed complex surgeries and developed a detailed understanding of human anatomy.
Pre-Socratic philosophers in
Ancient Greek culture brought natural philosophy a step closer to direct inquiry about cause and effect in nature between 600 and 400 BC. However, an element of magic and mythology remained. Natural phenomena such as earthquakes and eclipses were explained increasingly in the context of nature itself instead of being attributed to angry gods.
Thales of Miletus, an early philosopher who lived from 625 to 546 BC, explained earthquakes by theorizing that the world floated on water and that water was the fundamental element in nature. In the 5th century BC,
Leucippus was an early exponent of
atomism, the idea that the world is made up of fundamental indivisible particles.
Pythagoras applied Greek innovations in mathematics to astronomy and suggested that the earth was
spherical.
Aristotelian natural philosophy (400 BC–1100 AD) from the father Later
Socratic and
Platonic thought focused on ethics, morals, and art and did not attempt an investigation of the physical world; Plato criticized pre-Socratic thinkers as materialists and anti-religionists.
Aristotle, however, a student of Plato who lived from 384 to 322 BC, paid closer attention to the natural world in his philosophy. In his
History of Animals, he described the inner workings of 110 species, including the
stingray,
catfish and
bee. He investigated chick embryos by breaking open eggs and observing them at various stages of development. Aristotle's works were influential through the 16th century, and he is considered to be the
father of biology for his pioneering work in that science. He also presented philosophies about physics, nature, and astronomy using
inductive reasoning in his works
Physics and
Meteorology. by
Raphael. Plato rejected inquiry into natural philosophy as against religion, while his student, Aristotle, created a body of work on the natural world that influenced generations of scholars. While Aristotle considered natural philosophy more seriously than his predecessors, he approached it as a theoretical branch of science. Still, inspired by his work,
Ancient Roman philosophers of the early 1st century AD, including
Lucretius,
Seneca and
Pliny the Elder, wrote treatises that dealt with the rules of the natural world in varying degrees of depth. Many
Ancient Roman Neoplatonists of the 3rd to the 6th centuries also adapted Aristotle's teachings on the physical world to a philosophy that emphasized spiritualism. Early
medieval philosophers including
Macrobius,
Calcidius and
Martianus Capella also examined the physical world, largely from a cosmological and
cosmographical perspective, putting forth theories on the arrangement of celestial bodies and the heavens, which were posited as being composed of
aether. Aristotle's works on natural philosophy continued to be translated and studied amid the rise of the
Byzantine Empire and
Abbasid Caliphate. In the Byzantine Empire,
John Philoponus, an Alexandrian Aristotelian commentator and Christian theologian, was the first to question Aristotle's physics teaching. Unlike Aristotle, who based his physics on verbal argument, Philoponus instead relied on observation and argued for observation rather than resorting to a verbal argument. He introduced the
theory of impetus. John Philoponus' criticism of Aristotelian principles of physics served as inspiration for Galileo Galilei during the
Scientific Revolution. A revival in mathematics and science took place during the time of the
Abbasid Caliphate from the 9th century onward, when Muslim scholars expanded upon Greek and
Indian natural philosophy. The words
alcohol,
algebra and
zenith all have
Arabic roots.
Medieval natural philosophy (1100–1600) Aristotle's works and other Greek natural philosophy did not reach the West until about the middle of the 12th century, when works were translated from
Greek and Arabic into
Latin. The development of European civilization later in the Middle Ages brought with it further advances in natural philosophy. European inventions such as the
horseshoe,
horse collar and
crop rotation allowed for rapid population growth, eventually giving way to urbanization and the foundation of schools connected to monasteries and cathedrals in modern-day
France and
England. Aided by the schools, an approach to Christian
theology developed that sought to answer questions about nature and other subjects using logic. This approach, however, was seen by some detractors as
heresy. By the 12th century, Western European scholars and philosophers came into contact with a body of knowledge of which they had previously been ignorant: a large corpus of works in Greek and Arabic that were preserved by Islamic scholars. Through translation into Latin, Western Europe was introduced to Aristotle and his natural philosophy. These works were taught at new universities in
Paris and
Oxford by the early 13th century, although the practice was frowned upon by the Catholic church. A 1210 decree from the
Synod of Paris ordered that "no lectures are to be held in Paris either publicly or privately using Aristotle's books on natural philosophy or the commentaries, and we forbid all this under pain of ex-communication." In the late Middle Ages,
Spanish philosopher
Dominicus Gundissalinus translated a treatise by the earlier Persian scholar
Al-Farabi called
On the Sciences into Latin, calling the study of the mechanics of nature
Scientia naturalis, or natural science. Gundissalinus also proposed his classification of the natural sciences in his 1150 work
On the Division of Philosophy. This was the first detailed classification of the sciences based on Greek and Arab philosophy to reach Western Europe. Gundissalinus defined natural science as "the science considering only things unabstracted and with motion," as opposed to mathematics and sciences that rely on mathematics. Following Al-Farabi, he separated the sciences into eight parts, including: physics, cosmology, meteorology, minerals science, and plant and animal science. Later, philosophers made their own classifications of the natural sciences.
Robert Kilwardby wrote
On the Order of the Sciences in the 13th century that classed medicine as a mechanical science, along with agriculture, hunting, and theatre, while defining natural science as the science that deals with bodies in motion.
Roger Bacon, an English friar and philosopher, wrote that natural science dealt with "a principle of motion and rest, as in the parts of the elements of fire, air, earth, and water, and in all inanimate things made from them." These sciences also covered plants, animals and celestial bodies. Later in the 13th century, a Catholic priest and theologian
Thomas Aquinas defined natural science as dealing with "mobile beings" and "things which depend on a matter not only for their existence but also for their definition." There was broad agreement among scholars in medieval times that natural science was about bodies in motion. However, there was division about including fields such as medicine, music, and perspective. Philosophers pondered questions including the existence of a vacuum, whether motion could produce heat, the colours of rainbows, the motion of the earth, whether elemental chemicals exist, and where in the atmosphere rain is formed. In the centuries up through the end of the Middle Ages, natural science was often mingled with philosophies about magic and the occult. Natural philosophy appeared in various forms, from treatises to encyclopedias to commentaries on Aristotle. The interaction between natural philosophy and
Christianity was complex during this period; some early theologians, including
Tatian and
Eusebius, considered natural philosophy an outcropping of pagan Greek science and were suspicious of it. Although some later Christian philosophers, including Aquinas, came to see natural science as a means of interpreting scripture, this suspicion persisted until the 12th and 13th centuries. The
Condemnation of 1277, which forbade setting philosophy on a level equal with theology and the debate of religious constructs in a scientific context, showed the persistence with which Catholic leaders resisted the development of natural philosophy even from a theological perspective. Aquinas and
Albertus Magnus, another Catholic theologian of the era, sought to distance theology from science in their works. "I don't see what one's interpretation of Aristotle has to do with the teaching of the faith," he wrote in 1271.
Newton and the Scientific Revolution (1600–1800) By the 16th and 17th centuries, natural philosophy evolved beyond commentary on Aristotle as more early Greek philosophy was uncovered and translated. The invention of the printing press in the 15th century, the invention of the microscope and telescope, and the
Protestant Reformation fundamentally altered the social context in which scientific inquiry evolved in the West.
Christopher Columbus's discovery of a new world changed perceptions about the physical makeup of the world, while observations by
Copernicus,
Tyco Brahe and
Galileo brought a more accurate picture of the solar system as
heliocentric and proved many of Aristotle's theories about the heavenly bodies false. Several 17th-century philosophers, including
René Descartes,
Pierre Gassendi,
Marin Mersenne,
Nicolas Malebranche,
Thomas Hobbes,
John Locke and
Francis Bacon, made a break from the past by rejecting Aristotle and his medieval followers outright, calling their approach to natural philosophy superficial. (1571–1630). Kepler's
Astronomia Nova is "the first published account wherein a scientist documents how he has coped with the multitude of imperfect data to forge a theory of surpassing accuracy", therefore laying the groundwork for the scientific method. The titles of Galileo's work
Two New Sciences and
Johannes Kepler's
New Astronomy underscored the atmosphere of change that took hold in the 17th century as Aristotle was dismissed in favour of novel methods of inquiry into the natural world. Bacon was instrumental in popularizing this change; he argued that people should use the
arts and sciences to gain dominion over nature. To achieve this, he wrote that "human life [must] be endowed with discoveries and powers." He defined natural philosophy as "the knowledge of Causes and secret motions of things; and enlarging the bounds of Human Empire, to the effecting of all things possible." Bacon proposed that scientific inquiry be supported by the state and fed by the collaborative research of scientists, a vision that was unprecedented in its scope, ambition, and forms at the time. Natural philosophers came to view nature increasingly as a mechanism that could be taken apart and understood, much like a complex clock. Natural philosophers including
Isaac Newton,
Evangelista Torricelli and
Francesco Redi,
Edme Mariotte,
Jean-Baptiste Denis and
Jacques Rohault conducted experiments focusing on the flow of water, measuring
atmospheric pressure using a
barometer and disproving
spontaneous generation. Scientific societies and scientific journals emerged and were spread widely through the printing press, touching off the
Scientific Revolution. Newton in 1687 published his
The Mathematical Principles of Natural Philosophy, or
Principia Mathematica, which set the groundwork for physical laws that remained current until the 19th century. Some modern scholars, including Andrew Cunningham, Perry Williams, and
Floris Cohen, argue that natural philosophy is not properly called science and that genuine scientific inquiry began only with the scientific revolution. According to Cohen, "the emancipation of science from an overarching entity called 'natural philosophy is one defining characteristic of the Scientific Revolution." Other historians of science, including
Edward Grant, contend that the scientific revolution that blossomed in the 17th, 18th, and 19th centuries occurred when principles learned in the exact sciences of optics, mechanics, and astronomy began to be applied to questions raised by natural philosophy. Grant argues that Newton attempted to expose the mathematical basis of nature – the immutable rules it obeyed – and, in doing so, joined natural philosophy and mathematics for the first time, producing an early work of modern physics. is widely regarded as one of the most influential scientists of all time. The Scientific Revolution, which began to take hold in the 17th century, represented a sharp break from Aristotelian modes of inquiry. One of its principal advances was the use of the
scientific method to investigate nature. Data was collected, and
repeatable measurements were made in
experiments. Scientists then formed
hypotheses to explain the results of these experiments. The hypothesis was then tested using the principle of
falsifiability to prove or disprove its accuracy. The natural sciences continued to be called natural philosophy, but the adoption of the scientific method took science beyond the realm of philosophical conjecture and introduced a more structured way of examining nature. Newton, an English mathematician and physicist, was a seminal figure in the Scientific Revolution. Drawing on advances made in astronomy by Copernicus, Brahe, and Kepler, Newton derived the
universal law of gravitation and
laws of motion. These laws applied both on Earth and in outer space, uniting two spheres of the physical world previously thought to function independently, according to separate physical rules. Newton, for example, showed that the
tides were caused by the gravitational pull of the
Moon. Another of Newton's advances was to make mathematics a powerful explanatory tool for natural phenomena. While natural philosophers had long used mathematics as a means of measurement and analysis, its principles were not used as a means of understanding cause and effect in nature until Newton. In the 18th century and 19th century, scientists including
Charles-Augustin de Coulomb,
Alessandro Volta, and
Michael Faraday built upon Newtonian mechanics by exploring
electromagnetism, or the interplay of forces with positive and negative charges on
electrically charged particles. Faraday proposed that forces in nature operated in "
fields" that filled space. The idea of fields contrasted with the Newtonian construct of gravitation as simply "action at a distance", or the attraction of objects with nothing in the space between them to intervene.
James Clerk Maxwell in the 19th century unified these discoveries in a coherent
theory of electrodynamics. Using mathematical equations and experimentation, Maxwell discovered that space was filled with charged particles that could act upon each other and were a medium for transmitting charged waves. Significant advances in chemistry also took place during the Scientific Revolution.
Antoine Lavoisier, a French chemist, refuted the
phlogiston theory, which posited that things burned by releasing "phlogiston" into the air.
Joseph Priestley had discovered
oxygen in the 18th century, but Lavoisier discovered that
combustion was the result of
oxidation. He also constructed a table of 33 elements and invented modern chemical nomenclature. Formal biological science remained in its infancy in the 18th century, when the focus lay upon the
classification and categorization of natural life. This growth in
natural history was led by
Carl Linnaeus, whose 1735
taxonomy of the natural world is still in use. Linnaeus, in the 1750s, introduced
scientific names for all his species.
19th-century developments (1800–1900) was used to disprove that light propagated through a
luminiferous aether. This 19th-century concept was then superseded by
Albert Einstein's
special theory of relativity. By the 19th century, the study of science had come into the purview of professionals and institutions. In so doing, it gradually acquired the more modern name of
natural science. The term
scientist was coined by
William Whewell in an 1834 review of
Mary Somerville's
On the Connexion of the Sciences. But the word did not enter general use until nearly the end of the same century.
Modern natural science (1900–present) According to a famous 1923 textbook,
Thermodynamics and the Free Energy of Chemical Substances, by the American chemist
Gilbert N. Lewis and the American physical chemist
Merle Randall, the natural sciences contain three great branches: Aside from the logical and mathematical sciences, there are three great branches of
natural science which stand apart by reason of the variety of far reaching deductions drawn from a small number of primary postulates — they are
mechanics,
electrodynamics, and
thermodynamics. Today, natural sciences are more commonly divided into life sciences, such as botany and zoology, and physical sciences, which include physics, chemistry, astronomy, and Earth sciences. ==See also==