Science and Parascience is a history of psychical research between1914 and 1939. It's a sequel to Natural and Supernatural: A History of the Paranormal from the Earliest Times to 1914. This book explores the phenomena of mediumship, spontaneous cases and experimental investigations during WWI and the post-war period, in the UK, USA and European continent.

Along with eminent physicist Sir Oliver Lodge, who researched the subject extensively during the early twentieth century, Inglis concludes that the evidence is overwhelming stating: "I accept the evidence for the paranormal on precisely the same basis as I accept the evidence for, say, meteorites, or lightning, both of which were once in the supernatural category, but were taken out of it because the quantity of the evidence for them, and the quality of the sources, made continued scepticism impossible."

The Postscript chapter deals with its lack of acceptance, and in summing up, Inglis writes: "Psychical research had taken a wrong turning, in seeking academic recognition, if it meant losing contact with the public; an understandable but disastrous error of strategy which vitiated much of the valuable research undertaken between the wars, and unfairly destroyed the reputations of some of the most dedicated researchers. If I have done nothing else, I hope I have done something to rehabilitate them, at least in the eyes of their successors".