 Kuhn’s view of demarcation is most clearly expressed in his comparison of astronomy with astrology. Since antiquity, astronomy has been a puzzle-solving activity and therefore a science. If an astronomer’s prediction failed, then this was a puzzle that he could hope to solve for instance with more measurements or adjustments of the theory. In contrast, the astrologer had no such puzzles since in that discipline “particular failures did not give rise to research puzzles, for no man, however skilled, could make use of them in a constructive attempt to revise the astrological tradition” (Kuhn 1974, 804). Therefore, according to Kuhn, astrology has never been a science.