Philosophy of Being and Knowledge

Philosophy of Science

The Content of Scientific Theories

Positivists, Popper, Kuhn, Lakatos, and others have sought to answer the question of how science evolves. Alongside this crucial philosophical inquiry, an equally significant discussion in the philosophy of science concerns what exactly science apprehends: reality as it is or the creations of its own ingenuity. Philosophers who assert that science comprehends reality as it exists are known as realists. They claim that reality is constant and can be known, and that science is capable of encompassing it. Realism is divided into several schools:

• Scientific Realism is represented by Irish-American physicist and Catholic priest Ernan McMullin (1924-2011) and Greek philosopher Stathis Psillos (b. 1965). Proponents of this school believe that scientific theories discover reality as it truly is, meaning that science reveals the real facts of the world and the genuine relationships between them.
• Structural Realism is represented by British philosopher John Worrall (b. 1946). He posits that while scientists cannot apprehend the things of reality directly, they can know the true structures—i.e., the relationships between facts, patterns of existence, and the interactions of facts within reality.
• Objective Realism is represented by Canadian Ian Hacking (b. 1936) and American Nancy Cartwright (b. 1944). They argue that science is capable of knowing reality. Even if there is no reason to believe that scientific theories describe reality with absolute precision, the fact that scientific theories work is evident. If a scientific theory underpins technological advancements and yields expected results, this suffices to assert that the theory has correctly represented reality.

Not all philosophers of science agree with the notion that science comprehends reality. The question then arises: if not reality, what does science apprehend? Critics of realism contend that scientists do not replicate the world from reality but rather create it themselves. This raises a further question: by what criteria do scientists choose a worldview that is acceptable to them? In addressing this question, philosophers who reject realism have diverged into various schools, differing only in minor details:

• Conventionalism is a philosophical position founded by the French philosopher Henri Poincaré (1854-1912). Conventionalists believe that an accurate depiction of reality is impossible and thus not the aim of science. The purpose of science is to clarify reality, and therefore, a scientific theory is not a precise description of reality but a convention—a mutual agreement among scientists to recognize and use a particular theory. In such agreements, scientists focus not on the truth of the theory, which is unattainable, but on practical goals: if a theory fulfills its intended purposes, it is accepted by the scientific community.
• Instrumentalism is a position articulated by French philosopher Pierre Duhem (1861-1916), who held that a scientific theory is not required to be true. Scientists create theories that work, not those that are true; their interest lies in the practical results of science rather than theoretical truths. A scientific theory is a tool by which science and technology master the world. If this tool is effective, it is deemed scientific; if it fails to achieve its goals, scientists abandon it.
• Pragmatism is a philosophical movement developed in the United States, with founders including Charles Sanders Peirce (1839-1914), William James (1842-1910), and John Dewey (1859-1952). Pragmatists assert that the criterion of truth for any judgments is their utility. If a scientific theory is useful, then it is considered true, regardless of how well it corresponds to or accurately represents reality.
• Scientific Historicism is a philosophical stance represented by German philosopher Kurt Hübner (1921-2013). Adherents of this position believe that different epochs have different objectives for scientific theories, so the same theory may hold varying value for people in different times. Hübner’s position is close to Marxism and Kuhn’s theory.

Constructivism, a popular philosophical movement of the twentieth century, also influenced the philosophy of science. Constructivists argue that science, language, and knowledge are constructs of human creation, not always reflecting reality. In the philosophy of science, various forms of constructivism diverge in their responses to the question of criteria for the quality of scientific theories:

• Social Constructivism is represented by Austrian-American philosopher Peter Ludwig Berger (1929-2017) and German philosopher Thomas Luckmann (1927-2016). Followers of this approach believe that scientific theories are social constructs. Society creates explanations of reality, and these explanations constitute the content of science. For social constructivists, the criterion of a theory’s quality is its social utility. If a theory fulfills the tasks society sets for it, then it is deemed of high quality; if it does not, it should be abandoned.
• Radical Constructivism is a movement founded by German-American philosopher Ernst von Glasersfeld (1917-2010) and Swiss psychologist Jean Piaget (1896-1980). They argue that scientific theories are human constructs that are not related to reality but are created from subjective preferences.
• Empirical Constructivism is a branch of constructivism founded by Dutch scholar Bas van Fraassen (b. 1941). He argues that scientific theories are human constructs but must correspond to empirical data. If a theory does not match empirical observations, it is rejected by the scientific community.
• Constructive Realism is a position presented by Austrian philosopher Friedrich Wallner (b. 1945), who differentiates between reality and reality as perceived. Reality is what the world actually is, and it is inaccessible to science. Reality, on the other hand, is the worldview formed within a particular culture. The aim of science is to create constructs that express this perceived reality.