[6] According to Professor of Social Theory Alfred de Grazia at New York University, "By 1983 Ellenberger was preparing to abandon much of quantavolution and found now that the story of Velikovsky was not without its shady tones, and more important, that Arctic ice cores and bristlecone pine dating technologies were directly contradicting Holocene quantavolutions .

Velikovsky inscribed his copy of Ramses II and His Time 'To Leroy who is consumed by the sacred flame of search for truth', 20 May 1978, and gave him permission to sell 'Velikovsky's right!'

"[8] Also, he "has tried unceasingly but to little avail to have his former colleagues acknowledge the accumulating evidence, for example, from Greenland ice cores, that Velikovsky's claimed catastrophes did not in fact occur.

[14] While citing these publications, Richard J. Huggett, Senior Lecturer in Geography, University of Manchester, averred that Ellenberger "has, since his conversion to the anti-Velikovsky camp in 1984, relentlessly and mercilessly tried to show why Velikovsky's ideas were downright silly.

Previously, he was an invited speaker at Milton Zysman's August 1990 "Reconsidering Velikovsky" Conference at University of Toronto, identified on the program as "Velikovsky's most unrelenting critic" who was interviewed for The Globe and Mail,[23] and he was the keynote speaker at the August 1992 Canadian Society for Interdisciplinary Studies conference in Haliburton, Ontario.

"[26] His resignation from Kronos as senior editor in December 1986 was acknowledged by Martin Gardner,[27] who previously noted Ellenberger's "vitriolic" letters defending Velikovsky.

"[29] Sagan biographer Keay Davidson credits Ellenberger "In my experience" as "the single richest source of information on the Velikovsky controversy.

[31] NASA astronomer David Morrison, who has monitored the Velikovsky scene since 1972, has thanked Ellenberger for helping "to look at these issues from the other side and to appreciate how poorly the scientific critics communicated with the public.

"[32] Ellenberger's role as a Velikovsky turncoat and critic has been recently affirmed by Ronald H. Fritze in Invented Knowledge: False History, Fake Science and Pseudo-religions.

[33] Princeton historian Michael Gordin acknowledged "a special debt of gratitude" to Ellenberger for his contributions to The Pseudoscience Wars.