Contemporary science is typically subdivided into the natural sciences which study nature in the broadest sense, the social sciences which study people and societies, and the formal sciences like mathematics which study abstract concepts. Some do not consider formal sciences to be true science as theories within these disciplines cannot be tested with physical observations,:54 although others dispute this view. Either way, mathematics is a crucial tool for modern science and nowadays all science students need to take at least some basic mathematics courses during their studies. Disciplines which use science like engineering and medicine may also be considered to be applied sciences. Science is related to research, and is normally organized by a university, a college, or a research institute.
From classical antiquity through the 19th century, science as a type of knowledge was more closely linked to philosophy than it is now and, in fact, in the West the term "natural philosophy" encompassed fields of study that are today associated with science such as physics, astronomy, medicine, among many others.:3 In the 17th and 18th centuries scientists increasingly sought to formulate knowledge in terms of laws of nature. As a slow process over centuries, the word "science" became increasingly associated with what is today known as the scientific method, a structured way to study the natural world.
Science in a broad sense existed before the modern era and in many historical civilizations. Modern science is distinct in its approach and successful in its results, so it now defines what science is in the strictest sense of the term.
Science in its original sense was a word for a type of knowledge rather than a specialized word for the pursuit of such knowledge. In particular, it was the type of knowledge which people can communicate to each other and share. For example, knowledge about the working of natural things was gathered long before recorded history and led to the development of complex abstract thought. This is shown by the construction of complex calendars, techniques for making poisonous plants edible, public works at national scale, such which those which harnessed the floodplain of the Yangtse with reservoirs, dams, and dikes, and buildings such as the Pyramids. However, no consistent conscientious distinction was made between knowledge of such things, which are true in every community, and other types of communal knowledge, such as mythologies and legal systems.
Before the invention or discovery of the concept of "nature" (ancient Greek phusis) by the Pre-Socratic philosophers, the same words tend to be used to describe the natural "way" in which a plant grows, and the "way" in which, for example, one tribe worships a particular god. For this reason, it is claimed these men were the first philosophers in the strict sense, and also the first people to clearly distinguish "nature" and "convention.":209 Science was therefore distinguished as the knowledge of nature and things which are true for every community, and the name of the specialized pursuit of such knowledge was philosophy – the realm of the first philosopher-physicists. They were mainly speculators or theorists, particularly interested in astronomy. In contrast, trying to use knowledge of nature to imitate nature (artifice or technology, Greek technē) was seen by classical scientists as a more appropriate interest for lower class artisans.