The author of this treatise is not appearing here for the first time as a critic of psycho-analysis. This book suffers from the same lack of objectivity as earlier and shorter criticisms by him have done. He asserts that Freud and psycho-analysis have not furnished science with a single useful point of view. If this is so, it is hard to understand why the writer thinks it necessary to devote a whole book to the subject. I shall refrain from considering his objections in detail, because at so many points his opposition manifests itself underneath his ostensibly objective arguments.