The 'occult doubles' of the title are phrenology, mesmerism, spiritualism, psychical research and contemporary therapeutic cults. Each is examined to see to what extent the label 'pseudoscience' applies. The treatment of phrenology is long and sympathetic; the authors making the point that the central ideas of its founder Gall, a materialist theory of the mind, contains little that would seem odd today. The 'bump-reading' of cranioscopy was a corollary, although later practices elevated this into a central principal.
In contrast the treatment of Spiritualism is superficial and dismissive, being written off as a fraud, largely on the confessions of former medium Lama Keene. The major problems presented by such mental mediums as Piper and Leonard, or physical mediums such as Palladio and Home are simply ignored. Parapsychology is much more respectfully approached, and the Leaheys consider it methodologically at least, to be at worst an overambitious pre-science, at best a science.
However, as regards content, the jury is still out. They suggest two major problems confront parapsychology, parapsychologists, and their critics, who both tend to see the study in terms of naive falsification the 'one white crow' type of argument. On the contrary a successful research programme will not be overthrown by a few contrary facts. Secondly, a new generation of parapsychologists, in their eagerness to be 'scientific' and to harmonise parapsychology (or paraphysics) with quantum physics, are in danger of isolating themselves from the emotional depths of anti-materialism of the founders, and backing themselves into 'scientism': "Furthermore, the materialist scents the religious wolf in scientific sheep's clothing, Which threatens their freedom from the hellish tyranny of faith."
The account of the views of Popper, Lakates and Kuhn in the introduction is perhaps the most lucid I have seen. I actually understood what Lakatos is talking about. - Peter Rogerson, from Magonia 22, May 1986.