Pragmatism is a philosophical tradition that began in the United States around 1870. Its origins are often attributed to the philosophers William James, John Dewey, and Charles Sanders Peirce. Peirce later described it in his pragmatic maxim: "Consider the practical effects of the objects of your conception. Then, your conception of those effects is the whole of your conception of the object." 

Pragmatism considers thought an instrument or tool for prediction, problem solving and action, and rejects the idea that the function of thought is to describe, represent, or mirror reality. Pragmatists contend that most philosophical topics—such as the nature of knowledge, language, concepts, meaning, belief, and science—are all best viewed in terms of their practical uses and successes. The philosophy of pragmatism "emphasizes the practical application of ideas by acting on them to actually test them in human experiences". Pragmatism focuses on a "changing universe rather than an unchanging one as the Idealists, Realists and Thomists had claimed". 

Pragmatism as a philosophical movement began in the United States in the 1870s. Charles Sanders Peirce (and his Pragmatic Maxim) is given credit for its development, along with later twentieth century contributors, William James and John Dewey. Its direction was determined by The Metaphysical Club members Charles Sanders Peirce, William James, and Chauncey Wright, as well as John Dewey and George Herbert Mead.
What is an instrument for prediction?
Pragmatism considers thought an instrument or tool for prediction,