… is from page 169 of the 1996 Liberty Fund collection of Frank Meyer’s essays, In Defense of Freedom (William C. Dennis, ed.); specifically, it’s from Meyer’s March 28th, 1956, National Review article “In Defense of John Stuart Mill”:
The use of force against those who propound error is wrong, not because it is inexpedient but because it is an outrage upon the freedom of man and, in that, upon the very nature of man.


The use of force against those who propound error is wrong, not because it is inexpedient but because it is an outrage upon the freedom of man and, in that, upon the very nature of man.
