In the

philosophy of science Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ultim ...

, under the

correspondence principle In physics, the correspondence principle states that the behavior of systems described by the theory of quantum mechanics (or by the old quantum theory) reproduces classical physics in the limit of large quantum numbers. In other words, it says t ...

, a limiting case

theory A theory is a rational type of abstract thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking is often associated with such processes as observational study or research. Theories may be s ...

is an earlier theory which becomes incorporated into a later, usually broader theory; that is to say, the earlier (limiting case) theory proves to be a special or limited case of the later theory. Technically, a theory is said to be a limiting case of another, later theory when and if the later theory subsumes the theoretical relations and apparent referents of the earlier one. For example, physicists agree that

classical mechanics Classical mechanics is a physical theory describing the motion of macroscopic objects, from projectiles to parts of machinery, and astronomical objects, such as spacecraft, planets, stars, and galaxies. For objects governed by classical ...

constitutes a low-energy limiting case of

relativity theory The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena in ...

.Ladyman, James (2013): "Toward a Demarcation of Science from Pseudoscience", in ''Philosophy of Pseudoscience'', Chicago-London: The University of Chicago Press, p. 51. In words of

Larry Laudan Larry Laudan (; October 16, 1941 – August 23, 2022) was an American philosopher of science and epistemologist. He strongly criticized the traditions of positivism, realism, and relativism, and he defended a view of science as a privileged an ...

, realist philosophers use this phrase in the sense that the theory "T₁ can be a limiting case of

he theory He or HE may refer to: Language * He (pronoun), an English pronoun * He (kana), the romanization of the Japanese kana へ * He (letter), the fifth letter of many Semitic alphabets * He (Cyrillic), a letter of the Cyrillic script called ''He'' ...

T₂ only if (a) ''all'' the variables (observable and theoretical) assigned a value in T₁ are assigned a value by T₂ and (b) the values assigned to every variable of T₁ are the same as, or very close to, the values T₂ assigns to the corresponding variable when certain initial and boundary conditions—consistent with T₂—are specified". The idea that a theory (in our previous example,

Newtonian mechanics Newton's laws of motion are three basic laws of classical mechanics that describe the relationship between the motion of an object and the forces acting on it. These laws can be paraphrased as follows: # A body remains at rest, or in motion ...

) that is close to being true (i.e., that is

verisimil In philosophy, verisimilitude (or truthlikeness) is the notion that some propositions are closer to being true than other propositions. The problem of verisimilitude is the problem of articulating what it takes for one false theory to be close ...

) converges as a limiting case into a superior theory (in this example,

relativistic mechanics In physics, relativistic mechanics refers to mechanics compatible with special relativity (SR) and general relativity (GR). It provides a non-quantum mechanical description of a system of particles, or of a fluid, in cases where the velocities of ...

) can be an argument for

scientific realism Scientific realism is the view that the universe described by science is real regardless of how it may be interpreted. Within philosophy of science, this view is often an answer to the question "how is the success of science to be explained?" Th ...

, as the theoretical entities postulated by the previous theories are still considered existent (if one assumes semantic realism, they are considered existent because they are referred to) in the successor theories.

References

* ''A Confutation of Convergent Realism'',

, in "

Philosophy of Science Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ultim ...

" Vol. 48, No. 1 (Mar., 1981), p. 21, The University of Chicago Press. Online in https://www.jstor.org/stable/187066 Philosophy of science Science studies {{science-philo-stub