procedure for the construction of a scientific theory that will account for results obtained through direct observation and experimentation and that will, through inference, predict further effects that can then be verified or disproved by empirical evidence derived from other experiments.

Developed by Sir Isaac Newton (Newton, Sir Isaac) during the late 17th century (but named at a later date by philosophers of science), the hypothetico-deductive method assumes that properly formed theories arise as generalizations from observable data that they are intended to explain. These hypotheses, however, cannot be conclusively established until the consequences that logically follow from them are verified through additional observations and experiments. In conformity with René Descartes' Rationalism, the hypothetico-deductive method treats theory as a deductive system in which particular empirical phenomena are explained by relating them back to general principles and definitions. The method, however, abandons the Cartesian claim that those principles and definitions are self-evident and valid; it assumes that their validity is determined only by the exact light their consequences throw on previously unexplained phenomena or on actual scientific problems.