How does piecemeal realism evaluate different parts of a scientific theory?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

The Greek philosopher Plato — Realism Plato, marble portrait bust copied from an original of the 4th century bce; in the Capitoline Museums, Rome.

Piecemeal realism evaluates scientific theories by rejecting the practice of assessing a theory as a whole—either as entirely true or entirely false. Instead, it advocates for a more granular approach that judges specific components of a theory individually.1

Under this framework, scientists identify and retain parts of a theory that are responsible for its predictive successes, while discarding or labeling as false those parts that do not contribute to those successes or are contradicted by later evidence.1

A classic example of this is the work of Augustin-Jean Fresnel on the wave propagation of light. While his theory relied on the now-rejected concept of an ether, contemporary optics retains his mathematical treatment of wave motion because it remains approximately correct and accounts for experimental data. By separating the successful, "true" components from the erroneous ones, piecemeal realism maintains the realist connection between scientific success and truth without needing to defend the entire theoretical structure.1