Whats New by Bob Parks at UMd:

4. PERPETUUM MOBILE: "ALL GREAT TRUTHS BEGIN AS BLASPHEMIES."
This is the slogan of Steorn, a Dublin company that is assembling
a jury of scientists to evaluate a device using moving permanent
magnets to produce free energy. WN has exposed so many of these
devices in the past that it gets depressing. So this time we
examined the slogan instead. It's from George Bernard Shaw's
Anajanska [1919], but the full quote must have been been lost.
We've found the full quote: "All great truths begin as
blasphemies, but all blasphemies do not become great truths."

Erich J. Knight