I was first introduced to Mill's essay On Liberty when, as an undergraduate at the University of Singapore, I attended Rusi Khan's lucid lectures. These lectures and Frank Cioffi's lively participation in the ensuing discussion gave me an abiding interest in the essay. Since then I have benefited from the commentaries of others even when I have disagreed with them. I would like to acknowledge in particular the works of John Rees, Alan Ryan, and Richard Wollheim. The Mill News Letter has been a source of very useful information. The splendid work done by John A Robson and his associates at the University of Toronto Press in the publication of the Collected Works of John Stuart Mill has been an enormous helLike many others working in the areas of moral, legal, and political philosophy, I am greatly indebted to, and have been influenced by, the writings of H. L. A. Hart. I have also learnt much from conversations and correspondence with him. In many hours of discussion with John Gray, I have been helped towards a better understanding of Mill's arguments. I have also profited from conversations with Alan Montefiore and Joseph Raz, J. W. N. Watkins read an early version of part of Chapter 8, and gave me helpful comments. I read a version of Chapter 4 to a seminar in Oxford conducted by John Gray, Alan Ryan, and W. L. Weinstein and gained much from their comments. I should also like to record my appreciation of the encouragement given to me by David Spitz whose untimely death has robbed us of a dedicated teacher and a champion of the Millian values of liberty and tolerance. Monash University granted me study leave in 1979 without which I would not have been able to complete this book. I am also grateful to Balliol College for extending to me the hospitality of its Senior Common Room while I was in Oxford. My wife and daughter had to put up with me more than usual when I was writing the book. [vii/viii]

I wish to thank the respective editors and publishers for permission to use material from the following papers of mine:

“Mill on Self-Regarding Conduct.” Philosophy, 1968.

“Mill and Liberty.” Journal of the History of Ideas, 1969.

“Crime and Immorality.” Modern Law Review, 1969.

“Paternalism and Morality.” Ratio, 1971.

"Mill”s Stable Society.” The Mill News Letter, 1971.

”Enforcing a Shared Morality.” Ethics, 1972.

”The Liberal Theory of the Open Society”, in Dante Germino and Klaus von Beyme (eds.), The Open Society in Theory and Practice. The Hague: Martinus Nijhofff, 1974).

Review of Gertrude Himmelfarb, On Liberty and Liberalism: The Case of John Stuart Mill, Political Theory, 1975.

“Utilitarianism and Self-Regarding Conduct.” Australasian Journal of Philosophy, 1977.

“Blasphemy and Obscenity.” British Journal of Law and Society, 1978.

Melbourne, February 1980.