Professor Hans Eysenck of London University's Institute of Psychiatry stated "Unless there is a gigantic conspiracy involving some thirty university departments all over the world, and several hundred highly respected scientists in various fields, many of them originally skeptical to the claims of the psychical researchers, the only conclusion that the unbiased observer can come to is that there does exist a small number of people who obtain knowledge existing in other people's minds, or in the outer world, by means as yet unknown to science".