Astrology consists of a number of belief systems that hold that there is a relationship between astronomical phenomena and events or descriptions of personality in the human world. Astrology has been rejected by the scientific community for having no explanatory power for describing the universe. Scientific testing has found no evidence to support the premises or purported effects outlined in the astrological traditions.
Where astrology has made falsifiable predictions, it has been falsified. The most famous test was headed by Shawn Carlson and included a committee of scientists and a committee of astrologers. It led to the conclusion that natal astrology performed no better than a chance.
Astrology has not demonstrated its effectiveness in controlled studies and has no scientific validity, and is thus regarded as pseudoscience. There is no proposed mechanism of action by which the positions and motions of stars and planets could affect people and events on Earth in the way astrologers say they do that does not contradict well-understood, basic aspects of biology and physics. Although astrology has no scientific validity, astrological beliefs have impacted human historyCampion, Nicholas, 2008. A History of Western Astrology, Vol. 1, The Ancient World (first published as The Dawn of Astrology: a Cultural History of Western Astrology. London: Continuum. and astrology has helped to drive the development of astronomy.
Modern scientific inquiry into astrology is primarily focused on drawing a correlation between astrological traditions and the influence of seasonal birth in humans.
Introduction
The majority of professional astrologers rely on performing astrology-based personality tests and making relevant predictions about the remunerator's future. Those who continue to have faith in astrology have been characterized as doing so "in spite of the fact that there is no verified scientific basis for their beliefs, and indeed that there is strong evidence to the contrary". Astrophysicist Neil deGrasse Tyson commented on astrological belief, saying that "part of knowing how to think is knowing how the laws of nature shape the world around us. Without that knowledge, without that capacity to think, you can easily become a victim of people who seek to take advantage of you".
Historical relationship with astronomy
The foundations of the theoretical structure used in astrology originate with the Babylonians, although widespread usage did not occur until the start of the Hellenistic period after Alexander the Great swept through Greece. The exact demarcation of what a constellation is is cultural and varied between civilisations. Ptolemy's work on astronomy was driven to some extent by the desire, like all astrologers of the time, to easily calculate the planetary movements. Early Western astrology operated under the Ancient Greek concepts of the Macrocosm and microcosm, and thus medical astrology related what happened to the planets and other objects in the sky to medical operations. This provided a further motivator for the study of astronomy. While defending the practice of astrology, Ptolemy acknowledged that the predictive power of astronomy for the motion of the planets and other celestial bodies ranked above astrological predictions.
During the Islamic Golden Age, astronomy was funded so that the astronomical parameters, such as the eccentricity of the sun's orbit, required for the Ptolemaic model could be calculated to sufficient accuracy and precision. Those in positions of power, like the Fatimid Caliphate vizier in 1120, funded the construction of observatories so that astrological predictions, fuelled by precise planetary information, could be made.. Due to the prohibition of astrology within Islam, most were demolished during or shortly after construction.
The rejection of astrology in works of astronomy started in 1679, with the yearly publication La Connoissance des temps. Unlike the West, in Iran, the belief of heliocentrism was rejected until the start of the 20th century, in part motivated by a fear that this would undermine the widespread belief in astrology and Islamic cosmology in Iran. The first work, Falak al-sa'ada by Ictizad al-Saltana, aimed at undermining this belief in astrology and "old astronomy" in Iran was published in 1861. On astrology, it cited the inability of different astrologers to make the same prediction about what occurs following a conjunction and described the attributes astrologers gave to the planets as implausible.
Philosophy of science
Astrology provides the quintessential example of a pseudoscience since it has been tested repeatedly and failed all the tests.
Falsifiability Science and non-science are often distinguished by the criterion of falsifiability. The criterion was first proposed by philosopher of science Karl Popper. To Popper, science does not rely on induction; instead, scientific investigations are inherently attempts to falsify existing theories through novel tests. If a single test fails, then the theory is falsified.
Therefore, any test of a scientific theory must prohibit certain results that falsify the theory, and expect other specific results consistent with the theory. Using this criterion of falsifiability, astrology is a pseudoscience.
Astrology was Popper's most frequent example of pseudoscience. Popper regarded astrology as "pseudo-empirical" in that "it appeals to observation and experiment", but "nevertheless does not come up to scientific standards".
In contrast to scientific disciplines, astrology does not respond to falsification through experiment. According to Professor of neurology Terence Hines, this is a hallmark of pseudoscience.
"No puzzles to solve" In contrast to Popper, the philosopher Thomas Kuhn argued that it was not lack of falsifiability that makes astrology unscientific, but rather that the process and concepts of astrology are non-empirical. To Kuhn, although astrologers had, historically, made predictions that "categorically failed", this in itself does not make it unscientific, nor do the attempts by astrologers to explain away the failure by claiming it was due to the creation of a horoscope being very difficult (through subsuming, after the fact, a more general horoscope that leads to a different prediction).
Rather, in Kuhn's eyes, astrology is not science because it was always more akin to medieval medicine; they followed a sequence of rules and guidelines for a seemingly necessary field with known shortcomings, but they did no research because the fields are not amenable to research, and so, "They had no puzzles to solve and therefore no science to practise."
While an astronomer could correct for failure, an astrologer could not. An astrologer could only explain away failure but could not revise the astrological hypothesis in a meaningful way. As such, to Kuhn, even if the stars could influence the path of humans through life astrology is not scientific.
Progress, practice and consistency Philosopher Paul Thagard believed that astrology can not be regarded as falsified in this sense until it has been replaced with a successor. In the case of predicting behaviour, psychology is the alternative. To Thagard a further criterion of demarcation of science from pseudoscience was that the state of the art must progress and that the community of researchers should be attempting to compare the current theory to alternatives, and not be "selective in considering confirmations and disconfirmations".
Progress is defined here as explaining new phenomena and solving existing problems, yet astrology has failed to progress having only changed little in nearly 2000 years. To Thagard, astrologers are acting as though engaged in normal science believing that the foundations of astrology were well established despite the "many unsolved problems", and in the face of better alternative theories (Psychology). For these reasons Thagard viewed astrology as pseudoscience.
To Thagard, astrology should not be regarded as a pseudoscience on the failure of Gauquelin to find any correlation between the various astrological signs and someone's career, twins not showing the expected correlations from having the same signs in twin studies, lack of agreement on the significance of the planets discovered since Ptolemy's time and large scale disasters wiping out individuals with vastly different signs at the same time. Rather, his demarcation of science requires three distinct foci: "theory, community [and] historical context".
While verification and falsifiability focused on the theory, Kuhn's work focused on the historical context, but the astrological community should also be considered. Whether or not they: are focused on comparing their approach to others. have a consistent approach. try to falsify their theory through experiment. In this approach, true falsification rather than modifying a theory to avoid the falsification only really occurs when an alternative theory is proposed.
Irrationality For the philosopher Edward W. James, astrology is irrational not because of the numerous problems with mechanisms and falsification due to experiments, but because an analysis of the astrological literature shows that it is infused with fallacious logic and poor reasoning.
This poor reasoning includes appeals to ancient astrologers such as Kepler despite any relevance of topic or specific reasoning, and vague claims. The claim that evidence for astrology is that people born at roughly "the same place have a life pattern that is very similar" is vague, but also ignores that time is reference frame dependent and gives no definition of "same place" despite the planet's moving in the reference frame of the Solar System. Other comments by astrologers are based on severely erroneous interpretations of basic physics, such as the general belief by medieval astrologers that the geocentric Solar System corresponded to an atom. Further, James noted that response to criticism also relies on faulty logic, an example of which was a response to twin studies with the statement that coincidences in twins are due to astrology, but any differences are due to "heredity and environment", while for other astrologers the issues are too difficult and they just want to get back to their astrology. Further, to astrologers, if something appears in their favor, they may latch upon it as proof, while making no attempt to explore its implications, preferring to refer to the item in favor as definitive; possibilities that do not make astrology look favorable are ignored.
Quinean dichotomy From the Quinean web of knowledge, there is a dichotomy where one must either reject astrology or accept astrology but reject all established scientific disciplines that are incompatible with astrology.
Tests of astrology Astrologers often do not make verifiable predictions, but instead make vague statements that are not falsifiable. Across several centuries of testing, the predictions of astrology have never been more accurate than that expected by chance alone. One approach used in testing astrology quantitatively is through blind experiment. When specific predictions from astrologers were tested in rigorous experimental procedures in the Carlson test, the predictions were falsified. All controlled experiments have failed to show any effect.
Mars effect