What is "instrumentalism"

Instrumentalism \In`stru*men"tal*ism\, n. (Philos.) The view that the sanction of truth is its utility, or that truth is genuine only in so far as it is a valuable instrument. -- In`stru*men"tal*ist, n.

Instrumentalism views truth as simply the value belonging to certain ideas in so far as these ideas are biological functions of our organisms, and psychological functions whereby we direct our choices and attain our successes.
--Josiah Royce.

n. (context philosophy English) In the philosophy of science, the view that concepts and theories are merely useful instruments whose worth is measured not by whether the concepts and theories are true or false (or correctly depict reality), but how effective they are in explaining and predicting phenomena.

Instrumentalism is one of a multitude of modern schools of thought created by scientists and philosophers throughout the 20th century. It is named for its premise that theories are tools or instruments identifying reliable means-end relations found in experience, but not claiming to reveal realities beyond experience. Its premises and practices were most clearly and persuasively stated by two philosophers, John Dewey (1859-1952) and Karl Popper (1902-1994). Independently, they defined the school quite similarly, but their judgments of its premises were irreconcilable.

Dewey was a practitioner of instrumentalism, accepting means-end relations as discoverable by joining inductive and deductive reasoning about experience. Popper was a critic of the school. He insisted that induction is not scientifically valid, and that realities can be known without experience. These contrary judgments endowed the school with the legacy of confusion and ambiguity described below.

This article gives the definition of instrumentalism accepted by these two philosophers. It explains the grounds of their irreconcilable judgments, which are still embedded in popular understanding of the school, and describes the practice of followers of each philosopher, demonstrating that neither philosopher's judgments have achieved universal assent, leaving the school's meaning and legitimacy in modern scientific inquiry indeterminate.