Demarcation problem in the context of "Philosophy of science"

Pseudoscience consists of statements, beliefs, or practices that claim to be scientific or factual but are inherently incompatible with the scientific method. Pseudoscience is often characterized by contradictory, exaggerated or unfalsifiable claims; reliance on confirmation bias rather than rigorous attempts at refutation; lack of openness to evaluation by other experts; absence of systematic practices when developing hypotheses; and continued adherence long after the pseudoscientific hypotheses have been experimentally discredited. It is not the same as junk science.

The demarcation between science and pseudoscience has scientific, philosophical, and political implications. Philosophers debate the nature of science and the general criteria for drawing the line between scientific theories and pseudoscientific beliefs, but there is widespread agreement "that creationism, astrology, homeopathy, Kirlian photography, dowsing, ufology, ancient astronaut theory, Holocaust denialism, Velikovskian catastrophism, and climate change denialism are pseudosciences." There are implications for health care, the use of expert testimony, and weighing environmental policies. Recent empirical research has shown that individuals who indulge in pseudoscientific beliefs generally show lower evidential criteria, meaning they often require significantly less evidence before coming to conclusions. This can be coined as a 'jump-to-conclusions' bias that can increase the spread of pseudoscientific beliefs. Addressing pseudoscience is part of science education and developing scientific literacy.

Falsifiability is a standard of evaluation of scientific theories and hypotheses. A hypothesis is falsifiable if it belongs to a language or logical structure capable of describing an empirical observation that contradicts it. It was introduced by the philosopher of science Karl Popper in his book The Logic of Scientific Discovery (1934). Popper emphasized that the contradiction is to be found in the logical structure alone, without having to worry about methodological considerations external to this structure. He proposed falsifiability as the cornerstone solution to both the problem of induction and the problem of demarcation.

Popper also emphasized the related asymmetry created by the relation of a universal law with basic observation statements and contrasted falsifiability with the intuitively similar concept of verifiability that was then current in the philosophical discipline of logical positivism. He argued that the only way to verify a claim such as "All swans are white" would be if one could empirically observe all swans, which is not possible. On the other hand, the observation of a single black swan is enough to refute this claim.

Immanuel Velikovsky (/ˌvɛliˈkɒfski/; Russian: Иммануи́л Велико́вский, IPA: [ɪmənʊˈil vʲɪlʲɪˈkofskʲɪj]; 10 June [O.S. 29 May] 1895 – 17 November 1979) was a Russian-American psychoanalyst, writer, and catastrophist. He is the author of several books offering pseudohistorical interpretations of ancient history, including the U.S. bestseller Worlds in Collision published in 1950. Velikovsky's work is frequently cited as a canonical example of pseudoscience and has been used as an example of the demarcation problem.

His books use comparative mythology and ancient literary sources (including the Old Testament) to argue that Earth suffered catastrophic close contacts with other planets (principally Venus and Mars) in ancient history. In positioning Velikovsky among catastrophists including Hans Bellamy, Ignatius Donnelly, and Johann Gottlieb Radlof [de], the British astronomers Victor Clube and Bill Napier noted "... Velikovsky is not so much the first of the new catastrophists ...; he is the last in a line of traditional catastrophists going back to mediaeval times and probably earlier." Velikovsky argued that electromagnetic effects play an important role in celestial mechanics. He also proposed a revised chronology for ancient Egypt, Greece, Israel, and other cultures of the ancient Near East. The revised chronology aimed at explaining the so-called "dark age" of the eastern Mediterranean (c. 1100–750 BC) and reconciling biblical accounts with widely accepted archaeology and Egyptian chronology.

A fringe theory is an idea or a viewpoint that differs significantly from the accepted scholarship of the time within its field. Fringe theories include the models and proposals of fringe science, as well as similar ideas in other areas of scholarship, such as the humanities. In a narrower sense, the term fringe theory is commonly used as a pejorative, roughly synonymous with the terms pseudo-scholarship and conspiracy theory. Precise definitions distinguishing widely held viewpoints and unaccepted theories are difficult to construct. Issues of false balance or false equivalence can occur when fringe theories are presented as being equal to widely accepted theories.