The natural sciences are branches of science that seek to elucidate the rules that govern the natural world by using scientific methods. The term "natural science" is used to distinguish the subject matter from the social sciences, which apply the scientific method to study human behavior and social patterns; the humanities, which use a critical or analytical approach to study the human condition; and the formal sciences such as mathematics and logic, which use an a priori, as opposed to factual methodology to study formal systems.
There are five branches of natural science: astronomy, biology, chemistry, the Earth sciences and physics. This distinguishes sciences that cover inquiry into the world of nature from human sciences such as anthropology, sociology and linguistics, and from formal sciences such as mathematics and logic. Despite their differences, these sciences sometimes overlap; the social sciences and biology both study human beings as organisms, for example, and mathematics is used regularly in all the natural sciences.
The natural sciences are among the basic sciences, or scientific fields where study is motivated purely by curiosity. They also form the basis for applied sciences, however, which find real-world, practical applications for concepts and methods developed in basic science. In academic contexts, the natural and applied sciences are distinguished from the social sciences on the one hand, and the humanities on the other. Not all institutions and scientists are in agreement, however, about the classification of sciences and other academic disciplines.
Alongside its traditional usage, natural science may encompass natural history, which emerged in the 16th century and focused on the description and classification of plants, animals, minerals and other natural objects. Today, natural history refers to observational descriptions of the natural world aimed at popular audiences rather than an academic ones. The natural sciences are sometimes referred to colloquially as hard science, or fields seen as relying on experimental, quantifiable data or the scientific method and focusing on accuracy and objectivity. These usually include physics, chemistry and biology. By contrast, soft science is used a as a pejorative term to describe fields more reliant on qualitative research, including the social sciences.Aristotelian natural philosophy:
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 B.C., 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 19th century, and he is considered by some scholars to be the father of biology. He also presented philosophies about physics, nature and astronomy using inductive reasoning in his works Physics and Meteorology.
Plato (left) and Aristotle in a 1509 painting 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.
Aristotle's works on natural philosophy continued to be translated and studied amid the rise of the Byzantine Empire and Islam in the Middle East. A revival in mathematics and science took place during the time of the Abbasid Caliphate from the ninth century onward, when Muslim scholars expanded upon Greek and Indian natural philosophy. The words alcohol, algebra and zenith all have Arabic roots.