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. The philosopher Paul Thagard asserts that astrology cannot 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 is 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 views astrology as pseudoscience. 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. Effectiveness Astrology has not demonstrated its effectiveness in controlled studies and has no scientific validity. Where it has made falsifiable predictions under controlled conditions, they have been falsified. One famous experiment included 28 astrologers who were asked to match over a hundred natal charts to psychological profiles generated by the California Psychological Inventory (CPI) questionnaire. The double-blind experimental protocol used in this study was agreed upon by a group of physicists and a group of astrologers nominated by the National Council for Geocosmic Research, who advised the experimenters, helped ensure that the test was fair and helped draw the central proposition of natal astrology to be tested. They also chose 26 out of the 28 astrologers for the tests (two more volunteered afterwards). The study, published in Nature in 1985, found that predictions based on natal astrology were no better than chance, and that the testing "...clearly refutes the astrological hypothesis." In 1955, the astrologer and psychologist Michel Gauquelin stated that though he had failed to find evidence