Evolution of Scientific Knowledge: Popper, Kuhn, Feyerabend, Lakatos
According to Popper, the contrast of a theory and its conclusions must pass the following stages:
- Logical comparison of findings.
- Study of the logical form of a theory to determine its character.
- Comparison with theories to see if the theory will be considered a scientific breakthrough if it survives different contrasts.
- Contrasting the empirical application of the conclusions drawn from them.
Popper also rejected the distinction between theoretical and observational terms and tried to overcome the problem of induction by replacing the verifiability criterion with the falsifiability or refutation of the theory. For Popper, scientific theories are conjectures, subject to a constant process of trial and error. The distinctive feature of scientific theories is that they are subject to review and are formulated to allow their falsification. The confirmation of a theory should not be sought through experiments that confirm it positively in every case, but by the refutation of hypotheses: one refutation is enough to abandon a theory, while hundreds of confirmations cannot induce a universal law, valid forever. Popper’s approaches have been criticized, mainly because the history of science does not show an evolution of scientific theories that follow his proposed sequence of bold conjectures and constant falsification.
Scientific Knowledge and History of Science
Thomas Kuhn analyzes the characteristics of scientific knowledge from a different perspective than positivism and falsification. For Kuhn, defining scientific knowledge and its evolution is linked to the analysis of the history of science and the rational reconstruction of scientific progress. He describes the history of science as a process of revolutionary leaps in which periods of “normal science” alternate with periods of “revolutionary science.” Science is structured in paradigms involving a world view and the order of nature, around which scientific advances develop. Normal science is conducted by scientific communities that share a common disciplinary matrix (paradigm). In periods of normal science, the evolution of scientific knowledge is characterized by increased precision in the agreement between observations and calculations based on the paradigm, extending the scope of the paradigm, establishing the values of universal constants, and formulating quantitative laws also structured by the paradigm. Scientific activity seeks to expand conservatively, without undermining the shared paradigm. However, during this expansion, anomalies occur, leading to the invention of alternative paradigms incommensurable with each other. This leads to a period of revolutionary science, characterized by the triangular relationship between the established paradigm, a rival paradigm, and observational data. When a promising alternative paradigm emerges, science enters a revolutionary period until that paradigm is imposed, after which it enters a new period of normal science. The new paradigm should provide a quantitative increase in accuracy and a satisfactory treatment of the anomalies. The notion of paradigm has been widely criticized, and Kuhn attempted to clarify this concept further, ultimately blurring the contrast between normal and revolutionary science. Moreover, the incommensurability of paradigms has been strongly criticized by Lakatos and Stegmüller. For Feyerabend, the analysis of science must begin with a critique of radical empiricism. Radical empiricism is based on two assumptions to be satisfied by any scientific theory: consistency and meaning invariance. However, the meaning of terms depends on the theoretical context in which they appear, and new theories do not explain the old. Therefore, most scientific advances do not satisfy the conditions of consistency and invariance of meaning. Radical empiricism must be rejected because its two basic conditions are unreasonable and do not respond to the dynamics of human knowledge. Abandoning the positivist myth of the distinction between theoretical and observational terms transforms the debate about social sciences research, showing that science is closer to the arts. Feyerabend develops a “pragmatic philosophy of observation,” whereby observation statements are distinguished by the circumstances of their production. Observation reports are dependent on theories: the way one conceives the world depends on the theories held in a given context. The only way to verify or criticize a theory is in terms of other alternative or incompatible theories: if they have common observation statements, a crucial experiment can be performed; if not shared, the scientist should invent a more general theory or analyze internally conflicting theories. Lakatos sought a middle ground between logical empiricism and falsifiability. According to him, the history of science shows an evolution of scientific theories that are not completely autonomous but can be judged together. Lakatos focuses on what he calls “scientific research programs.” For him, great scientific discoveries are research programs that can be evaluated as progressive or standing. A scientific revolution is the replacement of one research program by another, leading to a new rational reconstruction of science. Compared to previous theories, Lakatos’s methodology of research programs provides criteria for choosing between rival programs. Progress is determined by authorities that verify an excess of content, rather than falsifying instances.
The Scientific Nature of TS Groups
We must highlight two important issues regarding the scientific status of TS groups:
- First, the difficulties regarding the verification and formulation of necessary causal laws, which have led to applying scientific truths in terms of probability, affecting both physical and social sciences: “all scientific measurement is given always with a probable error.” It is not only the likelihood of achieving about the outside world they may be neutral observers, but must understand the evolution of scientific theories based on the prior hermeneutical circle in which we find ourselves, and that defines the horizon of intelligibility. Any comments are already in a previous theory, but may be evolving beyond the theory that determines the meaning, and therefore it is possible scientific change and the choice between rival theories.
- Second, science is a fact/social process, a historical product of scientific communities. The inability to distinguish between theoretical and observational terms provides an important similarity between the social and physical sciences, as there is no neutral observation language.
In short, the scientific method is based on three commonly accepted assumptions and can be applied to TS groups:
Incommensurability: it is impossible to compare two theories when there is no common theoretical language. If two theories are incommensurable, there is no way to compare and say which is better.