A scientist, in a broad sense, is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word. Scientists perform research toward a more comprehensive understanding of nature, including physical, mathematical and social realms.
Philosophy can be seen as a distinct activity, which is aimed towards a more comprehensive understanding of intangible aspects of reality and experience that cannot be physically measured.
Scientists are also distinct from engineers, those who develop devices that serve practical purposes. When science is done with a goal toward practical utility, it is called applied science (short of the creation of new devices that fall into the realm of engineering). When science is done with an inclusion of intangible aspects of reality it is called natural philosophy.
Social roles that partly correspond with the modern scientist can be identified going back at least until 17th century natural philosophy, but the term scientist is much more recent. Until the late 19th or early 20th century, those who pursued science were called “natural philosophers” or “men of science”.
English philosopher and historian of science William Whewell coined the term scientist in 1833, and it was first published in Whewell’s anonymous 1834 review of Mary Somerville’s On the Connexion of the Physical Sciences published in the Quarterly Review.