"Liberals have learned, at fearful cost, the lesson that absolute power corrupts absolutely. They have yet to learn that absolute liberty may also corrupt absolutely."

Source

     Gertrude Himmelfarb, On liberty and liberalism:  the case of John Stuart Mill (New York:  Knopf, 1974), as quoted by Peter L. Berger in "Mill vs. Mill," Commentary 58, no. 4 (October 1974): 80-81.  I.e., the "absolute liberty" of the radically feminist Mill of On liberty, not the more carefully qualified liberty of the other Mill, whether before or after 1859.