Positivism, or positive philosophy, is a philosophical doctrine that denies any validity to metaphysics or speculation. It is sometimes associated with empiricism because it maintains that there is no answer to metaphysical questions and that scientific knowledge is the only knowledge. The works of English philosopher Francis Bacon (1561-1626), Anglo-Irish philosopher George Berkeley (1685-1753), and Scottish philosopher David Hume (1711-1776) contain the basic tenets of positivism in an implicit form. However, the term is specifically applied to the system of French philosopher and social scientist Auguste Comte (1798-1857), who developed the coherent doctrine and is the acknowledged founder of positivism.
According to positivists, while the methods of science can give people knowledge of the laws of coexistence and succession of phenomena, they can never penetrate to the inner essences of things. When the positive method is applied to the human world the result is a law of successive states through which each branch of knowledge must pass. The three states are theological, metaphysical and finally positive (or scientific). These successive states give Comte a law of the development of human society because the predominant intellectual forms determine the character of society. What made positivism possible was the cultural climate of the Industrial Revolution in the 18th century, which gave rise to a wave of optimism. Positivism turned this climate into a philosophical program, exalting science without concerning itself with the limits and the conditions of the validity of science and claiming that religion alongside ethics and politics would become scientific disciplines.
British philosopher John Stuart Mill (1806-1873), among others, admired the work of Comte and positivism became a popular movement in the second part of the 19th century. It accepted the concept of the infinity of nature and of history as well as of necessary and universal progress. Thus, it had affinities with the other important philosophical movement of the 19th century, absolute idealism, and they together belong in the general range of romanticism. Comte has wider and continuing influence in social science almost exclusively through his earlier writings. His views shifted later in his life as he was influenced by Clotilde de Vaux (1815-1846). As a result, Comte came to see that he had been wrong to suppose that science alone had the binding-force for social cohesion.
Critics of positivism tend to focus on the fact that natural-scientific methods are inappropriate in the human or social sciences. Consciousness, cultural norms, intentionality and symbolic meaning are variously considered distinctive human attributes that dictate a methodological gulf between the study of human social life and natural science. The American philosopher Thomas S. Kuhn (1922-1996) is regarded as one of the most influential philosophers of science of the 20th century. His work marked a break with positivism doctrines, along with the writings of Austrian-born philosopher of science Paul Feyerabend (1924-1994).
The two fundamental kinds of positivism are social positivism and evolutionary positivism. Both kinds share the general idea of progress but social positivism focuses on progress from a consideration of society and history, while evolutionary positivism has its roots in the fields of biology and physics. Key figures of social positivism are Comte and Mill, while English philosopher Herbert Spencer (1820-1903) represents evolutionary positivism. A third, critical type of positivism, developed in the last decade of the 19th century through the work of Austrian physicist and philosopher Ernst Mach (1838-1916) and German-Swiss philosopher Richard Avenarius (1843-1896). In Germany and Austria, this kind of positivism was known as empiriocriticism. Mach and Avenarius argued that science and knowledge in general is only an instrument used by the human organism to confront the infinite mass of facts, or sensations, in such a way as to conserve itself. Therefore, the function of science is economic and not contemplative or theoretical.
The chief results of empiriocriticism are theories that concern concepts and scientific laws very different from those of classical positivism. Forms of positivism that developed later, including logical positivism and neopositivism, which are directly related to critical positivism. Positivism and more usually logical positivism is also used to refer to the radical empiricism and scientism advanced at the beginning of the 20th century by the Vienna Circle. It is considered to be the main influence on sociological positivism, through the philosophy of theorists including Czech-American philosopher Ernest Nagel (1901-1985), philosopher of science Carl Gustav Hempel (1905-1997) and American sociologist Paul Lazarsfeld (1903-1976).