"Although both sides invoked the name of science in support of their ideas, this was, in Bowlby’s view, little more than a genuflection to Freud’s insistence that psychoanalysis should take its place as a new science of the mind.
Bowlby saw both women and most of their followers as hopelessly unscientific. Neither Klein nor Anna Freud had any kind of scientific background. Both argued from intuition and authority rather than subjecting their claims to empirical testing."
Jeremy Holmes – John Bowlby and Attachment Theory