- On the Web:
- Internet Encyclopedia of Philosophy - Pseudoscience and the Demarcation Problem (Oct. 23, 2026)
Pseudoscience
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What is pseudoscience?
Pseudoscience refers to beliefs or systems that try to explain the physical world but lack scientific proof. It includes theories, assumptions, and methods mistakenly regarded as scientific.
Pseudoscience is different from real science because its fundamental laws are unknown and unproven. Despite lacking evidence, pseudosciences such as astrology, graphology, and parapsychology remain popular.
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How is pseudoscience different from real science?
Pseudoscience is a system of theories, assumptions, and methods that are considered scientific but can't be proven through the scientific method. Unlike science, pseudoscience lacks the rigorous testing and empirical evidence needed to confirm its claims.
While science relies on observation, experimentation, and peer review to validate theories, pseudoscience often relies on anecdotal evidence, personal beliefs, or flawed reasoning. Pseudoscience often lacks self-correction; it does not evolve with new evidence, whereas science is constantly refined and updated based on new findings.
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What are some examples of pseudoscientific beliefs or practices?
Pseudoscience refers to beliefs or practices that are presented as scientific but lack the rigorous methodology and evidence of true science.
Examples include:
* Astrology Despite lacking scientific validity, astrology remains popular, with believers finding value in horoscopes and astrological readings.
* Phrenology This discredited practice claimed to determine a person's character and mental state based on the shape of their skull.
* UFO groups Some new religious movements (NRMs) claim scientific validity, such as UFO groups that incorporate religious themes into the language of technology and evolutionary theory.
* Quackery Exploits public interest in new discoveries with exaggerated claims and methods unknown to physicians or scientists.
* Conspiracy theories Explain events as the result of actions by a small, powerful group, rejecting accepted narratives.6 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Why do some people believe in pseudoscience?
Pseudoscience persists because it offers explanations that are not provable by the scientific method. People may believe in it due to cognitive biases, which are systematic errors in thinking that arise from subjective interpretations of reality. These biases can lead individuals to unconsciously favor information confirming their existing beliefs while overlooking contradictory evidence. Despite lacking empirical support, pseudosciences like astrology and parapsychology remain popular, with proponents often citing unexplained phenomena as proof of their legitimacy.
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How can you tell if a claim is pseudoscientific?
Pseudoscience is any explanatory system that cannot be proven by the scientific method. It is erroneously regarded as scientific, and its validity is often debated between scientists and pseudoscience practitioners.
Pseudoscience often relies on exaggerated claims, unusual terms, and the creation of fear, promising secrecy and financial savings. The lack of general knowledge encourages occultism, and those who promote quackery often claim to possess a formula, method, device, or product unknown to other physicians or scientists.
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What are the potential dangers of believing in or spreading pseudoscience?
Pseudoscience is any system that attempts to explain physical phenomena without the possibility of proof by the scientific method. Pseudoscience remains popular, especially astrology, parapsychology, and graphology. Pseudoscience proponents claim unexplained phenomena prove their beliefs, while opponents maintain that something cannot be a science if its fundamental laws are unknown and its existence unproven.
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Pseudoscience, any system that tries to explain physical phenomena but cannot be proved by the scientific method. Despite the fact that they are unproven, pseudosciences remain popular, especially astrology, parapsychology, and graphology. Their validity has been debated by scientists and pseudoscience practitioners for many years. While pseudoscience proponents claim that the number of unexplained phenomena on record is proof of the legitimacy of their beliefs, their opponents maintain that something cannot be a science if its fundamental laws are unknown and its existence remains unproven.
Astrology
Astrology is the study of heavenly bodies and their influence on life on Earth and has been popularized by books on the subject and by newspapers and magazines that carry horoscope columns. Modern astrologers use the relative positions of these heavenly bodies at the time of a personās birth to attempt to read the personās character and future.
The astrological system used most often in Western culture was developed by the ancient Greeks. The Egyptians, who contributed less directly to the modern system of astrology, constructed a calendar containing 12 months of 30 days each, with 5 days added at the end of the year. The Greeks later adapted this calendar as a standard of astronomical reference. The word horoscope comes from the Greek word hÅroskopos, meaning āhour watcher.ā
The Greeks believed that the Sun orbited Earth, and as it did it passed through the 12 constellations of the zodiac. It is now known that it is Earth that orbits the Sun and furthermore that the Sun does not move through or near any of the distant zodiacal stars.
Astrology has enjoyed a resurgence in the 2020s, especially among millennials and Generation Z. In a 2022 poll 27 percent of Americans said they believe in astrology, and the percentage was even higher, 37 percent, among those younger than 30. (See also astrology.)
Palmistry
The pseudoscience of palmistry attempts to diagnose disease, reveal character, and foretell the future by reading the lines and convolutions on the palm of the hand. The familiar form of palmistry is a Greek system, probably based on an older Indian tradition. After going in and out of fashion in Europe for several hundred years, palmistry underwent a revival in the 19th century, largely through the writings of Casimir dāArpentigny, William Benham, and Louis Harmon. In the 20th century, palmistry received renewed attention and interpretation by, among others, followers of Carl Jung.
Although there is no scientific proof for the contention that the physical features observed by palmists have psychic or predictive meaning, the human hand does show evidence of the personās health, cleanliness, occupation, and nervous habits. Since various palmists use different systems for reading and analyzing palm lines, different readings for the same hand are possible.
Phrenology
Phrenology is based on the idea that indentations and convolutions form on the human skull because of the presence or absence of certain mental faculties. Phrenologists believe that they can read a personās character and mental state by the overall shape of the skull.
About 1800, after studying criminals and mental patients, the German physician Franz Joseph Gall mapped 26 areas of the brainās surface that he claimed contained specific mental faculties. The system was constructed by a method of pure empiricism, and his so-called āorgansā were identified on quite specious grounds.
Later, Gallās system was revised and expanded by George Combe and Johann Spurzheim, who together mapped a total of 35 brain areas. Phrenology had popular appeal well into the 20th century but was eventually discredited by scientific research.
Numerology
Numerology uses numbers to describe a personās character and predict the future. The theory behind numerology is based on the Pythagorean idea that all things can be expressed in numerical terms because they are ultimately reducible to numbers. Using a special numerical system similar to that of the Greek and Hebrew alphabets, which assign a number to each letter, modern numerologists add up the digits of a personās name and birth date and then reduce them to a single digit for each. They then consult a numeric table that describes the personalities and fortunes of people with those numbers.
Graphology
Graphology, which is the determination of character through a personās handwriting, is based on the theory that handwriting is an expression of personality. When graphologists study handwriting, elements such as the size of individual letters and the degree and regularity of slanting, ornamentation, angularity, and curvature are noted as possible clues to the personās unconscious mind. Other basic considerations are the pressure of the strokes and the overall appearance of the writing. Graphology critics sometimes note that the system does not account for changes in handwriting with age and disease. (See also handwriting.)
Parapsychology
Parapsychology is the study of any phenomena that cannot be explained by natural law. It also refers to knowledge acquired by other than the usual sensory abilities (see senses). The term āpsiā is commonly used to denote all kinds of parapsychological phenomena. Usually included in extrasensory perception (ESP) are telepathy, or thought transference between persons; clairvoyance, or supernormal awareness of objects or events not necessarily known to others; and precognition, or knowledge of the future. Psychokinesis, also called telekinesis, is defined as the ability to influence physical objects by thought alone.
In 1882 the first foundation for psi studies, the Society for Psychical Research, was established in London. In 1888 the philosopher-psychologist William James founded a similar organization in the United States. Another psychologist, Joseph Rhine, began a series of famous psi experiments in the 1930s at Duke University in Durham, North Carolina. To test people for their ESP ability, Rhine had volunteers try to guess which of five symbols (a cross, a circle, a square, a star, or waves) was on the face of a specially designed card, called a Zener card. To study psychokinesis, Rhine had subjects try to will a pair of dice to fall into certain number combinations. Some scientists criticized Rhine for using poor experimental design and faulty statistical analysis. (See also extrasensory perception; spiritualism.)

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