Upton Sinclair took a gamble publishing this book. A lifelong Socialist who ran for high office several times, a muckraking author who had exposed the abuses of capitalism, was dabbling with what was seen as the occult. The impetus for this was his dear wife, Mary Craig Sinclair, known as 'Craig, ' who had been aware all her life that she could sense things that had not yet happened, or which she had no rational access to. In the late 1920s, this came to light when Craig had an odd feeling that their friend Jack London was in mental turmoil, just prior to London's suicide. The Sinclairs started to investigate how deep this particular rabbit hole went... The core of this book is a series of doodles which Upton and others made outside Craig's presence, which she was able to duplicate, apparently telepathically or through clairvoyance. Sinclair claims that Craig had over a 75% success rate over 290 tests, including 25% matches, and 50% partial matches. This success rate is obviously a lot higher than probability, considering that the potential set of drawings is a lot larger than, say, a deck of cards. Sinclair's top reputation as a 'speaker of truth to power' was actually a compelling reason to take this book seriously. The response to Mental Radio was very positive, impressing academics in the field of psychology and other scientists, including Albert Einstein, who wrote the introduction to the German edition. William McDougal, Chair of the Psychology Department at Duke University, who wrote the introduction for this edition, conducted his own experiments with Craig. McDougal and J.B. Rhine later went on to found the Parapsychology Laboratory at Duke, which conducted the first academic investigations of ESP. --Text refers the hardcover edition