The nineteenth century ushered in the philosophy of utilitarianism that was supposed to free man from ignorance and irrational behavior. It seems any means might be used to achieve this end – including falsity.
Stephen M. Klugewicz and Lenore T. Ealy write:
“Veracity was not either Mill’s main goal in retelling history. Indeed, John 
Stuart Mill followed his father in believing that, in striving to move mankind forward to a positivist, rationalist approach to life, philosophers must often teach through misdirection. The philosopher, in Mill’s view, has a duty to move mankind out of the shadows of religious ignorance and into the sunlight of pure reason. This goal made it necessary to eradicate religion, if necessary through falsehoods, in order to free individuals from the last vestige of the European old regime.” (Stephen M. Klugewicz and Lenore T. Ealy, History, on Proper Principles, Essays in Honor of Forrest McDonnald, ISI Books, Wilmington, Del., 2010, p. 254.)