Raymond Cattell, the father of personality trait measurement, was one of the most influential psychologists in the twentieth century, the author of fifty-six books, more than five hundred journal articles and book chapters, and some thirty standardized instruments for assessing personality and intelligence in a professional career that spanned almost seventy years. In August 1997, the American Psychological Association announced that Cattell had been selected the recipient of the American Psychological Foundation Gold Medal Award for Life Achievement in Psychological Science. Then, only two days before the scheduled ceremony, the APF abruptly postponed the presentation of the award due to concerns involving Cattell's views on racial segregation and eugenics._x000B__x000B_In addition to his mainstream research, Cattell had also authored a series of publications that posited evolutionary progress as the ultimate goal of human existence and argued that scientifically measurable criteria should be used to distinguish "successful" from "failing" racial groups so that the latter might be gradually "phased out" by non-violent methods such as regulation of birth control. Derived from science, Cattell's evolutionary philosophy was intended to be the basis of a full-blown religion. Although the earliest of these works had been published in the 1930s, near the end of an era in which eugenically based policies for human improvement were much more acceptable, Cattell promoted similar ideas well into the 1980s and '90s. _x000B__x000B_The Cattell Controversy describes Cattell's socio-religious beliefs in detail and analyzes their relationship to his scientific contributions. William H. Tucker discusses the controversy that arose within the field in response to the award's postponement, after which Cattell withdrew his name from consideration for the award but insisted that his position had been distorted by taking statements out of context. Reflecting on these events, Tucker concludes with a discussion of the complex question of whether and how a scientist's ideological views should ever be a relevant factor in determining the value of his or her contributions to the field.