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How can a scientific theory explain laws and predict new discoveries?

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Marble bust of Aristotle with a beard and draped robe, showing detailed facial features and wavy hair, set against a dark background. — Philosophy of science Aristotle, marble portrait bust, Roman copy (2nd century bce) of a Greek original (c. 325 bce); in the Museo Nazionale Romano, Rome.

In the philosophy of science, a scientific theory is a systematic, broad-scope framework that explains why empirical laws obtain and predicts new phenomena.12

Explaining Laws

Theories explain laws by serving as a postulational system—a set of premises from which empirical laws can be deduced as theorems. According to the deductive-nomological model championed by Carl Hempel, an explanation is an argument where the phenomenon to be explained is the conclusion. The premises must include at least one law of nature and specific conditions, demonstrating that the phenomenon was to be expected. By integrating various laws into a unified structure, theories provide a rational account of the orderliness observed in nature.134

Predicting New Discoveries

Unlike empirical laws, which are generalized from observed relationships, theories are imaginative constructions that often posit unobservable entities or mechanisms. Because theories possess greater scope than the laws they encompass, they can predict regularities or phenomena that have not yet been observed. When these theoretical parts are successfully applied to generate predictions—such as the prediction of the Poisson bright spot in optics—it provides evidence for the approximate truth of those theoretical claims.125