A scientist places an ad in a Paris newspaper offering a free horoscope. He receives about 150 replies, each, as requested, detailing a place and time of birth. Every respondent is then sent the identical horoscope, along with a questionnaire asking how accurate the horoscope had been. Ninety-four per cent of the respondents (and 90 per cent of their families and friends) reply that they were at least recognizable in the horoscope. However, the horoscope was drawn up for a French serial killer. If an astrologer can get this far without even meeting his subjects, think how well someone sensitive to human nuances and not overly scrupulous might do.

There may have been some time in the past when a group calling themselves astrologers could produce results. I don’t know, and the matter doesn’t interest me, for I live in the present. In our time the men working in the name of astrology are incapable of producing results, are conscious frauds.

No horoscope matches this accuracy. No theory of human causality, Freudian, Marxist, Christian or animist, has ever been so precise. No prophet in the Old Testament, no entrail-gazing oracle in ancient Greece, no crystal-ball gipsy clairvoyant on the pier at Bognor Regis ever pretended to tell people exactly when their lives would fall apart, let alone got it right. We are dealing here with a prophecy of terrifying, cruel and inflexible truth.

No horoscope matches this accuracy. No theory of human causality, Freudian, Marxist, Christian or animist, has ever been so precise. No prophet in the Old Testament, no entrail-grazing oracle in ancient Greece, no crystal-ball gypsy clairvoyant on the pier at Bognor Regis ever pretended to tell people exactly when their lives would fall apart, let alone got it right.

In all probability, the man who found the horoscope would also catch Nut and Nutcracker. They had to believe all the more strongly in the astrologer’s new forecast since none of his predictions had ever come true. Sooner or later, his prognoses had to be right, given that the king, who could never be wrong, had made him his Grand Augur.

The study he conducted with Dabholkar goes to explain why astrology is not a science through a simple experiment. They adopted an experiment conducted by Bernie Silverman, a graduate student of Michigan State University, USA. They collected horoscopes of 100 scholarly students and 100 students with learning difficulties.

The ultimate test of an explanation is whether it would have made the event predictable in advance. No story of Google’s unlikely success will meet that test, because no story can include the myriad of events that would have caused a different outcome. The human mind does not deal well with nonevents.

The Astronomer's fallacy. It is very hard to make a random selection of stars. If, for example, you see a star (with the naked eye) it is probably bright (as stars go). A lecturer was once making the point that middle class families were smaller than lower class ones. As a test he asked everyone to write down the number of children in his family. The average was larger than the lower class average. The obvious point he overlooked were that zero families were unrepresented in the audience. But further, families of n have a probability of being represented proportional to n; with all this, the result is to be expected.

Astrology provides a brilliant proof of the miserable subjectivity of human beings, as a result of which they relate everything to themselves and go from every thought in a straight line immediately back to themselves. It relates the course of the great celestial bodies to the pathetic I, as it also connects the comets in the sky with earthly quarrels and shabby tricks.

In contemporary Western society, buying a magazine on astrology - at a newsstand, say - is easy; it is much harder to find one on astronomy. Virtually every newspaper in America has a daily column on astrology; there are hardly any that have even a weekly column on astronomy. There are ten times more astrologers in the United States than astronomers. At parties, when I meet people that do not know I’m a scientist, I am sometimes asked “Are you a Gemini?” (chances of success, one in twelve), or “What sign are you?” Much more rarely am I asked “Have you heard that gold is made in supernova explosions?” or “When do you think Congress will approve a Mars Rover?”
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And personal astrology is with us still: consider two different newspaper astrology columns published in the same city on the same day. For example, we can examine The New York Post and the New York Daily News on September 21, 1979. Suppose you are a Libra - that is, born between September 23 and October 22. According to the astrologer for the Post, ‘a compromise will help ease tension’; useful, perhaps, but somewhat vague. According to the Daily News’ astrologer, you must ‘demand more of yourself’, an admonition that is also vague but also different. These ‘predictions’ are not predictions; rather they are pieces of advice - they tell you what to do, not what will happen. Deliberately, they are phrased so generally that they could apply to anyone. And they display major mutual inconsistencies. Why are they published as unapologetically as sport statistics and stock market reports?
Astrology can be tested by the lives of twins. There are many cases in which one twin is killed in childhood, in a riding accident, say, or is struck by lightning, while the other lives to a prosperous old age. Each was born in precisely the same place and within minutes of the other. Exactly the same planets were rising at their births. If astrology were valid, how could two such twins have such profoundly different fates? It a

Astrology and all these mystical things are generally signs of a weak mind; therefore as soon as they are becoming prominent in our minds, we should see a physician, take good food, and rest.

Royalty has traditionally been vulnerable to psychic frauds. In ancient China and Rome astrology was the exclusive property of the emperor; any private use of this potent art was considered a capital offense. Emerging from a particularly credulous Southern California culture, Nancy and Ronald Reagan relied on an astrologer in private and public matters — unknown to the voting public. Some portion of the decision-making that influences the future of our civilization is plainly in the hands of charlatans. If anything, the practice is comparatively muted in America; its venue is worldwide.

I do not attach too much importance to what astrologers say. In my case, they have never been right. Perhaps, my birth date is inaccurate. Nobody predicted I would be prime minister. Why prime minister? Nobody even predicted I would be chief minister.

So the forecast seems to have been quite good. The question is "What was it based on?" It was not... a prophecy, it was a scientific prediction because there is a specific mechanism on which it was based. ...[T]he forecast was a scientific prediction in the sense that I wanted to stick my neck out [and] make an out-of-sample prediction to see whether the mechanisms that have been identified by our theory... actually are working in the way that we thought...