Although this was expected, given his long fight with illness the past few years, it is very sad to realize that his voice is now silent in the debate about the nature of the phenomena that continue to fascinate us.
As you know, his writing and mine have followed a parallel course (I wish I had written JADOO, a delightful book!) as we were among a small number of “heretics” who have consistently questioned the “first-order” extraterrestrial theory. He realized very early that UFOs could not be understood apart from other, terrestrial paranormal phenomena, which put him decades ahead of most researchers. He deserves to be recognized as one of the most creative, independent thinkers in the field.
For anyone interested in the history of ufology, you really have to read the early books of these two author-researchers, such as Passport to Magonia and Operation: Trojan Horse.