1 Muehlmann, Robert G. ‘Introduction,’ in Berkeley's Metaphysics: Structural, Interpretive, and Critical Essays, Muehlmann, Robert G. ed. (University Park: Pennsylvania State University Press 1995), 1.Google Scholar

2 Pitcher, George Berkeley, Arguments of the Philosophers (London: Routledge and Kegan Paul 1977), 70.Google Scholar Cf. Winkler, Kenneth P. Berkeley: An Interpretation (Oxford: Clarendon Press 1989), 13;Google Scholar Muehlmann, Robert G. Berkeley's Ontology (Indianapolis: Hackett 1992), 49.Google Scholar

3 Winkler, Berkeley, 6Google Scholar

4 Bracken, Harry M. Berkeley, Philosophers in Perspective (New York: St. Martin's Press 1974),CrossRefGoogle Scholar 76ff.

5 Pappas, George Berkeley's Thought (Ithaca: Cornell University Press), 21-2Google Scholar

6 George Berkeley, A Treatise concerning the Principles of Human Knowledge, Part I, §1, in The Works of George Berkeley, Bishop of Cloyne, Luce, A.A. and Jessop, T.E. eds., 9 volumes (London: Nelson 1948-1957),Google Scholar 2:41. Further references to the Principles, Part I (PHK) will be made by section. References to the Introduction to the Principles (Intro.), will be made by section. References to Three Dialogues between Hylas and Philonous (DHP) will be to the appropriate page in Works, vol. 2. References to the Philosophical Commentaries (PC) will be by entry number in Works, vol. 1. References to An Essay towards a New Theory of Vision (NTV) will be by section. References to The Theory of Vision or Visual Language Vindicated and Explained (TW) will be by section. References to Alciphron, or The Minute Philosopher will be by dialogue and section.

7 Some help in this regard might be gained from the Philosophical Commentaries. I do not, however, treat texts from the Philosophical Commentaries as authoritative regarding either the philosophers to whom Berkeley was replying or the content of his philosophy. As Bertil Belfrage has shown, Luce's account of the marginalia is at least suspect. (See Belfrage, Bertil ‘George Berkeley's “Philosophical Commentaries, ” A Review of Prof. A.A. Luce's Editings,’ in Logik Rátt och Moral, Hallden, Sören et al., eds. [Lund: Studentlitteratur 1969] 19–34;Google Scholar Luce, A.A. ‘Another Look at Berkeley's Notebooks,’ Hermathena 110 [1970] 5–23;Google Scholar Bertil Beifrage, ‘Berkeley's Philosophical Notebooks,’ in Sosa, Ernest ed., Essays on the Philosophy of George Berkeley, Synthese Historical Library [Dordrecht: D. Reidel Publishing Company 1987] 217-30CrossRefGoogle Scholar.) If the Philosophical Commentaries were notebooks (Belfrage), rather than systematic commentaries (Luce), experience suggests there can be considerable conceptual distance between the Sketches in a notebook and the resulting polished product. Hence, I give them little sway.

8 See Flage, Daniel E. and Bonnen, Clarence A. Descartes and Method: A Search for Method in Meditations (London: Routledge 1999).Google Scholar

9 That Berkeley subscribed to the principle of parsimony seems reasonable since (1) it was commonly assumed throughout the period (see, for example, Descartes's Meteorology, quoted in The Philosophical Writings of Descartes (CSM), 3 vols., Cottingham, John Stooth off, Robert Murdoch, Dugald and [volume 3] Kenny, Anthony trans. [Cambridge: Cambridge University Press 1985, 1984, 1991],Google Scholar l:187n, see also Letter to Regius, Philosophical Writings of Descartes, 3:205), and (2) Berkeley seems to employ it his account of account of meaning contrary to the abstractionists at Intro. §§11-12 (see Flage, Daniel E. Berkeley's Doctrine of Notions: A Reconstruction based on his Theory of Meaning [London: Croom Helm 1987], 36-4Google Scholar).

10 For more see, Pappas, Berkeley's Thought, 160ff.; cf. Pitcher, Berkeley, 140-62.

11 PC 427a, 643; PHK §25; cf. PC 665; cf. Winkler, Kenneth P. Berkeley, 6Google Scholar and 157; Flage, Berkeley's Doctrine of Notions, 71.Google Scholar

12 PC 280, 684, 706; PHK §§27, 137, 140; DHP 231, 232; cf. Winkler, Berkeley, 13,Google Scholar Pitcher, Berkeley, 70-4; J.O. Urmson, Berkeley, in Dunn, John Urmson, J.O. and Ayer, A.J. The British Empiricists (Oxford: Oxford University Press 1984, 1982, 1980), 103;Google Scholar Copleston, Frederick Modern Philosophy: The British Empiricists, vol. 5,Google Scholar pt. II of his A History of Philosophy (Garden City: Doubleday Image Books 1964), 23; Park, Desiree ComplementaryNotions: A Critical Study of Berkeley's Theory of Concepts (The Hague: Martinus Nijh off 1972), 37;Google Scholar Tipton, Ian Berkeley: The Philosophy of Immaterialism (London: Methuen 1974), 165;Google Scholar Walmsley, Peter The Rhetoric of Berkeley's Philosophy, Cambridge Studies in Eighteenth Century English Literature and Thought, vol. 6 (Cambridge: Cambridge University Press 1990), 13–14.CrossRefGoogle Scholar It is worthy of notice that at no point does Berkeley deem an idea a mental image.

13 NTV §45, DHP 175, 250, 251; cf. Pappas, Berkeley's Thought, 173 and passim; Warnock, G.J. Berkeley, Pelican Philosophy Series (Hammondsworth: Penguin 1953), 158,Google Scholar but see also 195.

14 Cf. Intro. §7; Hicks, G.D. Berkeley (New York: Russell & Russell 1932), 156;Google Scholar Allaire, Edwin B. ‘Berkeley's Idealism,’ Theoria 29 (1963) 229-44,CrossRefGoogle Scholar but see also Edwin B. Allaire, ‘Berkeley's Idealism Revisited,’ in Turbayne, Colin ed., Berkeley: Critical and Interpretive Essays (Minneapolis: University of Minnesota Press 1982) 197–206;Google Scholar Bracken, Berkeley, 76ff; cf. Loeb, Louis From Descartes to Hume: Continental Metaphysics and the Development of Modern Philosophy (Ithaca: Cornell University Press 1981), 89–90;Google Scholar Flage, Berkeley's Doctrine of Notions, 152-4.

15 PHK §49, DHP 247; cf. Luce, A.A. Berkeley & Malebranche: A Study of the Origins of Berkeley's Thought (Oxford: Clarendon Press 1934), 67;Google Scholar Pitcher, 195; Yolton, John W. Perceptual Acquaintance from Descartes to Reid (Minneapolis: University of Minnesota Press 1984), 135.Google Scholar

16 Tipton, Berkeley, 20ff.; Walmsley, The Rhetoric of Berkeley's Philosophy, 14Google Scholar

17 Warnock, Berkeley, 146Google Scholar

18 Locke, John An Essay concerning Human Understanding, Nidditch, P.H. ed. (Oxford: Clarendon Press 1975),Google Scholar Book 4, Ch. 1, Sect. 1, 525 (further references to Locke's Essay will be by book, chapter, section, and page); cf. Descartes's discussions of objective reality at Meditations, CSM 2:28-9; Malebranche, Nicholas Elucidations of The Search afler Truth, in The Search After Truth and Elucidations of the Search After Truth, Lennon, Thomas M. and Olscamp, Paul J. trans. (Columbus: Ohio State University Press 1980), 561;Google Scholar Arnauld, Antoine and Nicole, Pierre Logic or the Art of Thinking, Buroker, Jill Vance trans. and ed., Cambridge Texts in the History of Philosophy (Cambridge: Cambridge University Press 1996), 26.CrossRefGoogle Scholar

19 Luce, A.A. The Dialectic of lmmaterialism (London: Hodder and Stroughton 1963), 30;Google Scholar cf. Flew, Antony An Introduction to Western Philosophy: Ideas and Argument from Plato to Sartre (Indianapolis: Bobbs-Merrill 1971), 339;Google Scholar Tipton, Berkeley,

20 I leave open the question whether Berkeley accepted the existence of simple ideas (see Winkler, Berkeley, 53-75). If inseparability — the actual or logical impossibility of forming an idea of a simple quality separated from all other ideas — were a sufficient condition for denying the existence of simple ideas, then even such Champions of simple ideas as Hume would seem committed to their nonexistence. (See David Hume, A Treatise of Human Nature, edited by L. A. Selby-Bigge, 2^nd edition revised by P.H. Nidditch [Oxford: Clarendon Press 1978], 2, 17-25.)

21 Locke, Essay HZA, 297; cf. 3.3.18, 418-19, 3.6.2-3, 439, 3.6.6-8, 442-4, 3.6.28, 455-6, 4.12.9, 644-5.

22 Locke, Essay 4.12.9, 644-5. See also Rene Descartes, Principles of Philosophy, Part I, §59, in CSM 1:212-13.

23 Our methodological constraints prohibit appealing to the passivity thesis in §25.

24 Cf. Descartes, Meditations, CSM 2:19

25 Cf. PC 74; DHP 202, 204 [knows], 199 [comprehends] (Hylas), and 212, 215, 234 [knows], 240 [understands], 231, 250 [comprehends] (Philonous); TW §26; Alciphron, Dialogue 4, §8. This is also suggested in PHK §27, where Berkeley writes, 'A spirit is one simple, undivided, active being: as it perceives ideas, it is called the understanding, and as it produces or otherwise operates about them, it is called the will.'

26 Locke, Essay 2.1.9, 108 27 Locke, Essay 2.1.4, 105. See also Malebranche, The Search afler Truth, 7-8; Spinoza, Benedict Ethics, in The Collected Works of Spinoza, vol. 1, Curley, E.M. ed. and trans. (Princeton: Princeton University Press 1985), 435,Google Scholar 448, 449, 457, 462, 469, 471, 477, 480, 481, 486, 487, 488, 504, 550, 555, 566, and 596; G.W. Leibniz, Discourse on Metaphysics, in Leibniz, G.W. Philosophical Essays, Ariew, Roger and Garber, Daniel trans. and ed. (Indianapolis: Hackett 1989),Google Scholar 59 and 65; Collier, Arthur Clavis Universalis (London 1713; reprinted in the British Philosophers and Theologians of the 17^th and 18^th Centuries, New York: Garland 1978), 8.Google Scholar

28 Yolton, Perceptual Acquaintance, 135.Google Scholar Winkler also acknowledges that Berkeley sometimes seems to use ‘to know’ and ‘to perceive’ as synonymous. See Winkler, Berkeley, 172.Google Scholar

29 George Pappas has argued that the evidence that Berkeley held esse is percipi to be a necessary truth is questionable, since Berkeley ‘says that either the denial of the principle is a contradiction or the denial is meaningless’ (Berkeley's Thought, 103). If my account is correct, then at least in the Prindples, Berkeley held that the denial of esse is percipi is meaningless because it is self-contradictory.

30 Hume, David An Enquiry concerning Human Understanding, in Enquiries concerning the Human Understanding and concerning the Principles of Marals, SelbyE, L.A. ed., 3^ld edition revised by Nidditch, P.H. (Oxford: Clarendon Press 1975), 155n.Google Scholar

31 Descartes, The Principles of Philosophy, Part I, §51, CSM 1:210

32 Pappas, Berkeley's Thought, 85;Google Scholar cf. Dancy, Jonathan Berkeley: An Introduction (London: Basil Blackwell 1987), 62ff.;Google Scholar Luce, Berkeley's Immaterialism, 62Google Scholar

33 Luce, Berkeley's Immaterialism, 62;Google Scholar cf. Bennett, Jonathan Locke, Berkeley, Hume: Central Themes (Oxford: Clarendon Press 1971), 70-4Google Scholar

34 Winkler, Berkeley, 178-9

35 Notice that in §95 Berkeley writes, ‘Take away this material substance, about the identity whereof all the dispute is, and mean by body what every plain ordinary person means by that word, to wit, that which is immediately seen and felt, which is only a combination of sensible qualities, or ideas: and then their most unanswerable objections come to nothing.’ Notice also that epistemic realism is consistent with both direct or naive realism and phenomenalism, since both claim that one has direct epistemic access to ‘real things.’ This distinction between access and analysis is sometimes blurred. See, for example, Dancy, Berkeley, 62ff.

36 (4’) cannot be reached by way of (I), since a syllogism with (4) and (I) as premises would commit the fallacy of illicit process of the major term. If Berkeley took the terms ‘idea’ and ‘object of knowledge’ as extensionally equivalent, the Substitution would be unproblematic. As we agreed above, however, such a reading is inconsistent with some of the later Berkeleian texts. Nonetheless, if we recognize that (4’) is a more general principle of which (4), that ‘No ideas exist unknown’ is an instance, it is reasonable to substitute (4’) for (4). So long as Berkeley is concerned with actual objects of knowledge, rather than possible or potential objects of knowledge, (4’) seems to be a necessary truth, asserting no more than that all (actually) known things are (actually) known.

37 (6’) should be understood as commonsensical truth.

38 For a more complete defense of this interpretation see Flage, Daniel E. ‘Berkeley on Abstraction,’ Journal of the History of Philosophy 24 (1986) 483–501.CrossRefGoogle Scholar

39 Cf. Descartes, Meditations, CSM 2:54.

40 That Berkeley was aware of this entailment is clear from the First Draft of the Introduction. See Works, 2:125.

41 Nor need one here read ‘idea’ as ‘object of knowledge.’ See Pitcher, Berkeley, 93Google Scholar

42 I wish to thank Robert Muehlmann for this objection.

43 McCracken, Charles J. ‘Berkeley on the Relation of Ideas to the Mind,’ in Minds, Ideas, and Objects: Essays on the Theory of Representation in Modern Philosophy, Cummins, Phillip D. and Zoeller, Guenter eds., North American Kant Society Studies in Philosophy, volume 2 (Atascadero, CA: Ridgeview 1992), 191Google Scholar

44 An alternative Interpretation of the second horn points to logical impossibility. Since objects are divided into kinds on the basis of resemblance, and given that the properties of ideas do not resemble the putative properties of an alleged material substance, claiming resemblance between two things that do not resemble is selfcontradictory. If a claim is self-contradictory, it represents an impossible State of affairs. If what is conceivable is logically possible, then what is logically impossible is inconceivable, so a likeness between and idea and a nonidea as understood by the ‘materialists’ is inconceivable. If this is understood as supporting the claim that the Position of the proponents of material substance in particular is inconceivable, fine. If it is taken as something close to Berkeley's entire argument, I do not believe it is plausible since (a) the likeness principle is general and, therefore, should not be restricted to a particular account of nonideas, (b) the allusion to ‘whether it be sense’ in the second horn is at least ambiguous between the possibility of forming a positive idea and the analysis of two descriptions to determine whether they are consistent, and (c) Berkeley uses the likeness principle to block inferences from ideas to putative nonideas. Given (a) and (c), I consider it plausible to suggest that Berkeley's defense of the likeness principle is based on appeals to conceivability, and if that is so, the mode of impossibility to which he alludes is most plausibly epistemic impossibility.

45 Locke, Essay 2.8.15, 137

46 See Locke, Essay 2.8.9-10 and 17; see also Boyle, Robert ‘The Origin of Forms and Qualities,’ in Selected Philosophical Papers of Robert Boyle, Stewart, M.A. ed. (New York: Barnes and Nobles 1979), 42.Google Scholar

47 On extension see §5. On figure see §§1, 3, 5, 7, and 8. On motion see §§1 and 7. While Berkeley does not allude directly to solidity or impenetrability, his allusion to resistance in §1 might be taken as a reference to solidity, since Locke recognized that solidity is perceived only insofar as one perceives resistance (Essay 2.4.1).

48 Locke, Essay 2.8.15

49 Cf. Descartes, Meditations, in Philosophical Writings, 2:29; Malebranche, Search After Truth, 59Google Scholar and 61; on Cudworth see Kenneth P. Winkler, ‘Ideas, Sentiments, and Qualities’ in Cummins and Zoeller, Minds, Ideas, and Objects, 151-2.

50 Locke, Essay 2.8.8, 134

51 Suarez, Francisco On Efficient Causality: Metaphysical Disputations 17, 18, and 19, Freddoso, Alfred ed. (New Haven: Yale University Press 1994),Google Scholar Disputation 18, §7, 131-77, and Disputation 17, Introductory Remarks, 3. For a careful discussion of Aristotle's, Aquinas's, and Suarez's criteria for deeming a cause an efficient cause, see Jorge, Secada ‘Descartes on Time and Causality’ Philosophical Review 99 (1990), 49–51.Google Scholar

52 CSM 2:147

53 See Locke, Essay 2.25.5; cf. PHK §142. See also Flage, Berkeley's Doctrine of Notions, 157-67.

54 Locke, Essay 2.16.1, 205

55 Muehlmann, Berkeley's Ontology, 122;Google Scholar see also his long and insightful discussion of the argument from perceptual relativity in the Three Dialogues, Berkeley's Ontology, 131-69, in which Muehlmann argues that even in the Three Dialogues the primary function of the argument from perceptual relativity is to undermine materialism, rather than to defend idealism.

56 Cf. Locke, Essay 2.23.2, 295-6. Similarly, Descartes in his scientific moments focused on a modified atomic theory, while in his philosophical moments focused on the traditional language of substance.

57 Cf. Essay 2.8.2, 132 and 2.23.3, 296; cf. Arnauld and Nicole, Logic, 45 and 126; Reid, Thomas Essays on the Active Powers of the Human Mind, Brody, Baruch ed. (Cambridge: MIT Press 1969), 7.Google Scholar See Flage, Daniel E. ‘Locke's Relative Ideas,’ Theoria 47 (1981) 142-59CrossRefGoogle Scholar; Flage, Daniel E. ‘Berkeley's Notions,’ Philosophy and Phenomenological Research 45 (1985) 407-25;CrossRefGoogle Scholar Flage, Berkeley's Notions, 134-42.

58 Garber, Daniel ‘Something-I-Know-Not-What: Berkeley on Locke on Substance,’ in Essays on the Philosophy of George Berkeley, edited by Sosa, Ernest (Dordrecht: D. Reidel 1987), 29Google Scholar

59 Locke, John A Letter to the Bishop of Worcester, in The Works of John Locke, 10 vols. (London, 1823;Google Scholar reprint edition Darmstadt: Scientia Verlag Aalen 1963), 2:21-2

60 For discussion of the “materialists” position on the explanation of ideas by means of primary qualities see Nancy L. Maull, ‘Berkeley on the Limits of Mechanistic Explanation,’ in Turbayne, Berkeley, 95-107.

61 PHK §20. This is followed by an anticipation of his explanation of the origin of ideas as things caused by God (cf. §29), a position which introduces no ontological category distinct from mind and is, therefore, simpler than a theory that posits material substance, and some remarks on the virtues of rejecting material substance on the basis of the philosophical and theological conundrums it generates (§21).

62 Pappas, Berkeley's Thought, 141-4; George Pappas, ‘Berkeleian Idealism and Impossible Performances,’ in Muehlmann, Berkeley's Metaphysics, 127-45, especially 142.

63 Winkler, Berkeley, 184;Google Scholar Tipton, Berkeley, 158-78; Pitcher, Berkeley, 113-15; cf. Moore, G.E. ‘The Refutation of Idealism’ in his Philosophical Studies (London: Routledge & Kegan Paul 1922), 1–30.Google Scholar

64 Cf. §73, where Berkeley provides a history of material substance and, after contending that he has shown that the primary qualities are mind-dependent, he concludes with the epistemic language, ‘it follows that we have no longer any reason to suppose the being of matter’ [my emphasis]. See also §88.

65 Descartes, Meditations, CSM 2:52-53; Locke, Essay 4.11.5, 633.

66 Cf. Pitcher, Berkeley, 133;Google Scholar Bennett, Locke, Berkeley, Hume, 165,Google Scholar though Bennett acknowledges, ‘the argument's conclusion falls short of theism, let alone Christian monotheism.’

67 While in §§30-33 Berkeley invites us to identify the cause of those ideas we do not cause ourselves with God, we should notice that in §146, where Berkeley provides his version of the teleological argument for the existence of God, he cites §29 as showing only that there must be some cause of those ideas we do no produce ourselves. If he were to defend his Suggestion in §29 that there is a Single cause of ideas we do not produce ourselves, Berkeley presumably would appeal to parsimony.

68 Cf. Descartes, Discourse on Method, CSM 1:129-30; see also Flage and Bonnen, Descartes and Method, 237-51.

69 Descartes, Meditations, CSM 2:61-62; Locke, Essay 2.1.16-17, 13

70 Locke, Essay 4.11.8, 634

71 If we became familiar with the behavior of citrus fruit before becoming familiar with the behavior of apples, and if we came to notice that citrus fruit spoils in predictable ways when left in the open air, then we might imagine that apples would behave in similar ways and, at least tentatively, include rotting behaviors in our notion of an apple.

72 This work was supported by the James Madison University Program of Grants for Faculty Educational Leaves. An earlier version of Part II was given in October 2000 as the 2000-01 Madison Scholar Lecture of the College of Arts and Letters at James Madison University. I wish to thank Jorge Secada, Ronald Glass, and the modern philosophy editor and three anonymous readers for the Canadiern Journal of Philosophy for their helpful comments on earlier versions of this paper.