All truth passes through three stages.
First, it is ridiculed.
Second, it is violently opposed.
Third, it is accepted as being self-evident.- attributed, probably inaccurately, to Arthur Schopenhauer (1788-1860) (there are no published citations to him as a source for this quote prior to 1951).
Other attributions are to Dr. J. Marion Sims, Richmond & Louisville Medical Journal, Vol. 7, p. 290 (1868) (similar but not verbatim) and to Sir James Mackenzie (1853-1925) in The Beloved Physician, by R. M. Wilson, John Murray, London.
All sources would reflect the lessons learned by the direct inheritors of (but not the participants in) the Age of Englightenment.
The saying may have been a source the concept that was later elaborated into the "five stage of grief".