"In his On Liberty (1858) and in his Representative Government (1861) Mill produces formal arguments which are designed to show that liberty, in particular liberty of thought and expression, is necessary for the development of human society. Progress, he argues, depends upon the freedom of individuals to innovate and experiment; conformity inevitably produces stagnation. This is the utilitarian basis of his argument against fully fledged democracy, that it is likely to produce a tyranny of the majority which will stifle those individual forces in society which give it life and meaning. For James Mill democracy had been a weapon to destroy the power of the 'sinister interest'; for his son it was a potential threat to liberty and social diversity, the mainsprings of human progress."