1 Eliot, George Daniel Deronda (New York: New American Library 1979) 355Google Scholar

2 For an account of the notion of common knowledge and its role in social conventions, see Lewis, David Convention (Cambridge: Harvard University Press 1969), esp. 52–60.Google Scholar

3 Chisholm, Roderick and Feehan, Thomas ‘The Intent to Deceive,’ The Journal of Philosophy 74 (March 1977) 143-59CrossRefGoogle Scholar

4 Strictly speaking, there will be a contradiction in the scientist's will if he believes that communicating his skepticism about the Bible will give the fundamentalist pause. If he does not believe this, openness appears to be compatible with the intention to deceive. But in such cases it is unclear that the intention to deceive-that is, to produce a belief that one regards as false-is morally wrong. Pointing out to the convinced holder of an opposing theory that her view has certain consequences may merely expand her stock of what, by one's own lights, are false beliefs. But if she is mentally competent, deception of this sort, even when intentional, seems to involve no contempt for her autonomy.

5 Sidgwick, Henry The Methods of Ethics, 1907 Edition (New York: Dover 1966) 317Google Scholar

6 Mill, J. S. Utilitarianism (Indianapolis: Bobbs-Merrill 1957) Chap. 5Google Scholar

7 Kant, Immanuel Foundations of the Metaphysics of Morals, trans. Beck, Lewis White (Indianapolis: Bobbs-Merrill 1959) 48 (429-30 of the Preussische Akademie edition)Google Scholar

8 Adherence to the principle of openness also seems to be required by the first version of the categorical imperative-at least if we accept the interpretation of it provided by Onora O'Neill Nell in her book Acting on Principle (New York: Columbia University Press 1975). According to this interpretation, one tests a maxim of action for moral acceptability by considering whether general acceptance of this maxim, together with the normal presuppositions and consequences of general acceptance, would prevent the intention expressed by the maxim from being realized. But if individuals seeking to get others to respond in certain ways routinely concealed facts that they thought their respondents would regard as relevant to the decision whether to respond, and this became generally known (as it would if it such behavior were routine), it would be difficult or impossible to get others to respond as one wished.

9 Chisholm and Feehan, 145

10 Cf. Lewis, David ‘Languages and Language,’ in Gunderson, Keith ed., Minnesota Studies in the Philosophy of Science VII (Minneapolis: University of Minnesota Press 1975), 3–35.Google Scholar Lewis writes that, ‘a language L is used by a population P if and only if there prevails in P a convention of truthfulness and trust in L, sustained by an interest in communication’ (10).

11 This account has the consequence that when deception by commission it is effected without the use of language, and when the agent does not want to elicit any further reasoned response (when he wants simply to produce a false belief for its own sake), it is no worse than failing to eliminate ignorance or false belief that contributes to a reasoned response that an one has done something to elicit. For both involve only one violation of the principle of openness. But this result seems acceptable.

12 I am indebted to Herbert Fingarette, Noel Fleming, Peter Hylton, and Nathan Salmon for helpful comments on an earlier version of this paper. I have also received helpful comments from anonymous referees for the Canadian Journal of Philosophy.