1 On this idea, see the original article: W.B. Gallie, 'Essentially Contested Concepts' Proceedings of the Aristotelian Society, 1955–6, vol. 56, particularly pp. 171ff. On attempts to define ideology, see: R. Geuss, The Idea of a Critical Theory, Cambridge University Press, Cambridge, 1981, Pt I; M. Hamilton, 'The Elements of a Concept of Ideology', Political Studies, 1987, vol. 35, pp. 18ff; and T. Eagleton, Ideology, Verso, London, 1991, Ch. 1.
2 On ideology as no mere reflection but an active agent moulding the desires of those in its thrall, see: J. Elster, 'Belief, Bias and Ideology', in M. Hollis and S. Lukes, eds, Rationality and Relativism, Blackwell, Oxford, 1982.
3 J. Habermas, Towards a Rational Society, Heinemann, London, 1970, p. 99. For a similar view of the modernity of ideology see, for example, K. Mannheim, Studies on the Left, Routledge, London, 1952, p. 55 and M. Oakeshott, Rationalism in Politics and Other Essays, Methuen, London, 1962, p. 21.
4 See further on this the excellent article: B. Halpern, '[Myth] and [Ideology] in Modern Usage'. History and Theory, vol. 1, 1961, especially pp. 135ff.
5 See Ch.7.
6 Baron d'Holbach. The System of Nature (translated by H.D. Robinson), Burt Franklin, New York, 1970, pp. viiiff.
7 K. Marx, Selected Writings, ed. D. McLellan, Oxford University Press, Oxford, 1977, p. 156.
8 Quoted in H. Barth, Wahrheit und Ideologic, Eugen Reutsch Verlag, Zurich and Stuttgart, 1961, p. 27.