The stars are grouped together not because they are actually close together in space but because they appear to be close together when seen from Earth. Further, different cultures group the stars in different ways and see different constellations in the sky. The only way these apparent groupings of stars called the constellations could have any special influence over human beings is through some unspecified sort of magic.
Ptolemy, the great astronomer and astrologer who lived in the second century C.E., also based his astrology on magical associations between the stars and planets and human behavior (Thorndike 1923). During the Middle Ages in Europe, great emphasis was placed on the authority of previous writers. Ptolemy was considered to be the greatest astrologer of the ancient world, so his writings on astrology were accepted and passed down in this way (Thomdike 1923, vol. 1). Thus, modern astrologers’ claims that their “science” is based on thousands of years of experimental and empirical observation are simply untrue; in fact, modern astrology rests largely on Ptolemy’s writings.
Certainly, views about the exact nature of the hypothesized influences of specific stars and planets on human behavior have changed over the centuries, and differences of opinion did and do exist among astrologers. Speaking of the Renaissance period, Shumaker (1972) states: “There has never, perhaps, been a time when conflicting opinions [about how astrology should be practiced] were not held and practices were not being modified. If at first glance such tinkering might be thought to imply constant experimental rectification, no one who has read much [medieval or Renaissance] astrological literature is likely to believe this was the cause of the alterations” (p. 11). Shumaker has found no experimental studies of astrology. Instead, astrology was justified by appeal “regularly to authorities… or to abstract reason” (p. 11). It is only in the twentieth century that statistical tests of astrological predictions have been attempted. These are reviewed later in this chapter.
ASTROLOGY AND ASTRONOMY
Astrologers are fond of claiming that their craft is a science and that astronomy is merely an offshoot of astrology. As seen from the above, however, the basic structure of astrological hypotheses has hardly changed at all over the last twenty-five hundred years. Greek astrologers believed, based on magical associations, that someone born under the influence of the planet Venus would love beauty and be a sensitive person. This type of lore, passed down through generations, is still accepted by modem astrologers, in spite of the fact that in the four thousand-year history of astrology, no astrologer has ever tried to see if the hypothesized relationships between heavenly bodies and human behavior really exist. Astrologers have never conducted research to support their claims. In chapter 1 it was pointed out that one of the chief characteristics of a pseudoscience is a refusal to change in the light of new evidence. Knowledge of astronomy and astrophysics has changed immensely since the Greeks looked up at the stars and saw their gods there. In spite of this, astrology has not changed at all—it is a static, stale pseudoscience.
On those few occasions when astrologers have made attempts to change astrological practice and theory, the nature of the attempts further reveals the pseudoscientific nature of astrology. In 1970, for example, astrologer Steven Schmidt argued that there are really fourteen signs of the zodiac, not twelve. According to Schmidt, the constellations Cetus and Ophiuchus should be added to the familiar set of twelve. From a purely astronomical point of view, there is much to recommend this change. The Sun does, in fact, pass through these two constellations in addition to the signs of the zodiac. Schmidt’s problem was to determine the character traits associated with these two “new” signs of the zodiac. Nowhere in his book does he present any data or suggest an adequate method of discovering what these traits might be. Rather, he simply “collected people” and “examined their character traits” (Schmidt 1970, p. 18). The people he examined were hardly a representative or random sample, since they included movie stars, past presidents (dead and alive), famous politicians, and so forth. The method used is utterly worthless scientifically.
One of the best examples of astrology’s refusal to change in the light of new knowledge is its failure to take into account the astronomical phenomenon of precession. The assignment of certain dates to certain signs of the zodiac (e.g., Aries ruling the period from March 21 to April 19) was made two thousand years ago (Abell 1981a) and has been followed by astrologers ever since. When it is said that the Sun is “in” Aries between March 21 and April 19, this means that the Sun, as seen from Earth, is in the same part of the sky as is the constellation Aries. The correspondences between the twelve constellations of the zodiac and their assigned dates were correct two thousand years ago—but not today. Earth “wobbles” slowly as it rotates, and because of this the position of the Sun relative to the constellations of the zodiac (as seen from Earth) changes over the centuries. By now, the difference is almost one complete sign—so the Sun is not in Aries from March 21 to April 19, but in Pisces for most of that period. Thus, if you are an Aries (born between March 21 and April 19), the sun was almost certainly not in Aries when you were born, but in Pisces! Most astrologers have been making predictions and casting horoscopes for the wrong signs for all these years. Many so-called tropical astrologers are aware of precession but choose to ignore it, arguing that somehow the “signs remember the influence of the constellations that corresponded to them two thousand years ago” (p. 86). This does not explain “why those same signs do not also recall the influence of other constellations that corresponded with them in even earlier millennia” (p. 86).
Astrologers claim that astrology is a science. When confronted with the fact that their “science” has hardly changed at all in the last two thousand years, they respond that astrology was so well established twenty centuries ago that there has never been any need to change, in spite of the vast changes that have taken place in our knowledge of the universe over the same period of time. Linda Goodman, best-selling author of popular books on astrology, sums up the astrologers’ position by saying, “Alone among the sciences, astrology has spanned the centuries and made the journey intact. We shouldn’t be surprised that it remains with us, unchanged by time— because astrology is truth—and truth is eternal” (Goodman 1971, p. 475).
Unfortunately for astrologers and their “ancient truths,” these “truths” are not true. The best example is the ancient astrological teaching that there are only seven heavenly bodies, other than Earth, in the solar system—the Sun, the Moon, Mercury, Venus, Mars, Jupiter, and Saturn. All ancient astrological teachings, the same that have been handed down to the likes of Linda Goodman, had this as a basic tenet. Unfortunately, it is totally wrong. Three additional planets have been discovered since the eighteenth century—Uranus in 1781, Neptune in 1846, and Pluto in 1930. These planets, which can be seen only through telescopes or binoculars, were unknown to the ancient astrologers.
The ability to derive, test, and verify or falsify predictions is one of the most important characteristics of science. Astrologers never predicted the existence of the three outer planets, and never even had the slightest hint that the planets existed—until astronomers discovered them. On the other hand, astronomers predicted the existence of Neptune twelve years before it was first identified through observation, and also predicted with great accuracy just where in the sky it could be found. It is in the discovery of Neptune that the contrast between the pseudoscience of astrology and the science of astronomy is most clearly seen. The exciting intellectual detective story of the discovery of Neptune is told in detail in Grosser’s
The prediction of the existence of a planet beyond Uranus was based on observed irregularities in Uranus’s orbit. Uranus was discovered in 1781, and astronomers noted almost at once that its orbit was irregular and could not be predicted with the same ease as the orbits of the other planets. In 1834 the British astronomer Thomas Hussey was the first to suggest that the perturbations of Uranus’s orbit were caused by the gravitational influence of an as-yet-unknown planet (Grosser 1962). In the early 1840s two young scientists, the English mathematician John Couch Adams and the French astronomer Urbain Jean Joseph Leverrier, independently began working on the problem of Uranus’s orbit with the goal of finding the unknown planet that was responsible for the perturbations. Their predictions were tested in 1846, and the previously unknown planet was found to be almost exactly where Adams and Leverrier had said it would be found.
Today, astrologers claim to understand the astrological influences of the three new planets. The addition of the new planets didn’t even cause much fuss among astrologers when they were discovered (Culver and Ianna 1984). But for nearly two thousand years, apparently not one astrologer ever noticed a planetary influence where there was no known planet, or was able to predict the existence or location of additional planets. Again, the history of astrological practice is inconsistent with the astrologers’ claims that astrology is a precise science. If, as
