George Berkeley

Berkeley, George (1685–1753)

George Berkeley, who was born in Ireland and who eventually became Bishop of Cloyne, is best known for three works that he published while still very young: An Essay towards a New Theory of Vision (1709), Three Dialogues between Hylas and Philonous (1713), and in particular for A Treatise concerning the Principles of Human Knowledge (1710). In the Principles he argues for the striking claim that there is no external, material world; that houses, trees and the like are simply collections of ‘ideas’; and that it is God who produces ‘ideas’ or ‘sensations’ in our minds. The New Theory of Vision had gone some way towards preparing the ground for this claim (although that work has interest and value in its own right), and the Dialogues represent Berkeley’s second attempt to defend it. Other works were to follow, including De Motu (1721), Alciphron (1732) and Siris (1744), but the three early works established Berkeley as one of the major figures in the history of modern philosophy.

The basic thesis was certainly striking, and from the start many were tempted to dismiss it outright as so outrageous that even Berkeley himself could not have taken it seriously. In fact, however, Berkeley was very serious, and certainly a very able philosopher. Writing at a time when rapid developments in science appeared to be offering the key to understanding the true nature of the material world and its operations, but when scepticism about the very existence of the material world was also on the philosophical agenda, Berkeley believed that ‘immaterialism’ offered the only hope of defeating scepticism and of understanding the status of scientific explanations. Nor would he accept that his denial of ‘matter’ was outrageous. Indeed, he held that, if properly understood, he would be seen as defending the views of ‘the vulgar’ or ‘the Mob’ against other philosophers, including Locke, whose views posed a threat to much that we would ordinarily take to be common sense. His metaphysics cannot be understood unless we see clearly how he could put this interpretation on it; and neither will we do it justice if we simply dismiss the role he gives to God as emerging from the piety of a future bishop. Religion was under threat; Berkeley can probably be judged prescient in seeing how attractive atheism could become, given the scientific revolution of which we are the heirs; and though it could hardly be claimed that his attempts to ward off the challenge were successful, they merit respectful attention. Whether, however, we see him as the proponent of a fascinating metaphysics about which we must make up our own minds, or as representing merely one stage in the philosophical debate that takes us from Descartes to Locke and then to Hume, Kant and beyond, we must recognize Berkeley as a powerful intellect who had an important contribution to make.

1 Life

George Berkeley was born in (or near) the town of Kilkenny, Ireland, and educated at Kilkenny College and at Trinity College, Dublin, where he took the degree of B.A. in 1704, and that of M.A. in 1707, becoming a Junior Fellow in the latter year. Before long he published the books for which he is now most renowned. However, mention must first be made of two notebooks, now known as the Philosophical Commentaries, which he filled during the years 1707–8. Since their first publication in 1871 (but more particularly since it was established that they had at some stage been bound together in the wrong order, thus giving a distorted picture of the development of Berkeley’s thought) these have proved an invaluable resource for scholars seeking to understand the evolution of his thinking during this crucial period. The major fruits of that thinking were An Essay towards a New Theory of Vision (1709), A Treatise concerning the Principles of Human Knowledge (1710) – which was originally intended to be merely Part I of a three- or four-part work– and the Three Dialogues between Hylas and Philonous (1713), which Berkeley published after he had moved to London. In between the Principles and Dialogues he published a slighter work, Passive Obedience (1712), which gives the main insight into his thinking on ethics, and on the basis of which he has been described as a theological rule-utilitarian. Also dating from about this time there are essays published in Richard Steele’s Guardian during the year 1713, which evidence his disdain for the antireligious sentiments of the ‘free-thinkers’.

From this time onwards, Berkeley’s life was active and interesting. He made two continental tours, the first (1713–14) as chaplain to Lord Peterborough, during which he apparently met Malebranche, and the second (1716–20) as tutor to George Ashe, son of the Bishop of Clogher. Towards the end of the second tour he wrote the Latin tract De Motu for submission to the Royal Academy of Sciences at Paris, which had offered a prize for an essay on the cause of motion. He published this in 1721, returned to Ireland in the same year, and was appointed Dean of Derry in 1724. Already, however, he had conceived a remarkable project that was to dominate his life for ten years. During the spring of 1722 he resolved to found a college on the island of Bermuda, and before long he set about soliciting support for and gaining a charter for St Paul’s College, which would, had it come into existence, have educated a number of young Native Americans, as well as the sons of English planters.

In fact he never reached Bermuda but, newly married, he set sail for Rhode Island in 1728, where he stayed for over two years awaiting a promised government grant, and where his house is preserved as a monument to him. The grant never materialized, so there was to be no college, either in Bermuda or, as he had come to think would be preferable, on the mainland. His time in Rhode Island was not, however, wasted. While there he wrote Alciphron: or the Minute Philosopher, an attack on atheism and deism in dialogue form, which was published in 1732, the year after his return to London. He also became a friend of Samuel Johnson, later the first president of King’s College, New York. Johnson’s Elementa Philosophica (1752) is dedicated to Berkeley, and two letters from Johnson written in 1729 and 1730 (published with Berkeley’s replies in volume two of the standard edition of Berkeley’s Works ) reveal that he was basically sympathetic to, but also an acute critic of, Berkeley’s main metaphysical doctrines.

Certainly the same could not be said of Andrew Baxter, who in 1733 included as part of his Enquiry into the Nature of the Human Soul what was, in fact, the first extended critique of Berkeley’s Principles. Baxter’s tone was hostile throughout. Berkeley chose not to respond, though in the same year he did answer an anonymous critic of the New Theory of Vision – a third edition of which had been annexed to Alciphron – by publishing The Theory of Vision, Vindicated and Explained. He also published a revised edition of the Principles and Dialogues in 1734. The Analyst (1734), which criticizes Newton’s doctrine of fluxions, also relates to his earlier work in that Berkeley refers back to his observations on mathematics in the Principles, and it may be that remarks Baxter had made on his treatment of the mathematicians there played at least a minor role in encouraging him to publish it. Berkeley does not name the critic who, he says, had challenged him to ‘make good’ what he had said in the Principles, but if it was Baxter he treats him dismissively as someone who ‘doth not appear to think maturely enough to understand either those metaphysics which he would refute, or mathematics which he would patronize’ ( The Analyst §50).

However, Berkeley also had to think about securing his and his family’s future, and his efforts to gain preferment in the church were rewarded in 1734 when he was appointed Bishop of Cloyne in Ireland. There, he thoroughly earned the reputation he has had ever since as ‘the good Bishop’. The tangible legacy includes The Querist (1735–7), which evidences his concern for the economic wellbeing of Ireland, and Siris (1744), so successful at the time that it went through six editions in the year of publication but which is now regarded as little more than a curiosity. However, this was to be his last original publication of any substance. He remained in Cloyne almost to the end of his life, moving to Oxford, where one of his sons was to study, in the summer of 1752. He died there in the following year.

2 Influences

The primary influence on Berkeley is unquestionably John Locke, whose Essay concerning Human Understanding Berkeley had studied as an undergraduate and continued to dwell on afterwards. The long introduction to Berkeley’s Principles is for the most part a sustained attack on the view that we can frame abstract ideas, focusing on Locke’s account of abstraction. Illegitimate abstraction is ultimately blamed for the supposedly untenable distinction between primary and secondary qualities, the belief in ‘material substance’, and the view that objects have an existence distinct from ‘ideas’, all of which are features of Locke’s position (see Locke, J. §§2–5). Yet Berkeley also owed a great deal to Locke whom he likened in the notebooks to ‘a Gyant’ and who should be seen as his mentor as well as one of his philosophical targets. It is therefore understandable that Berkeley has most often been seen as the second of the three great British Empiricists, as successor to Locke and precursor of Hume, these three being placed in opposition to the three great Rationalist philosophers, Descartes, Spinoza and Leibniz . Certainly, it would be tempting to say that the importance of Locke’s influence on Berkeley could hardly be overestimated, were it not for the fact that it sometimes has been.

If only as a corrective, then, it is important to stress that while it is evident that Locke was often in Berkeley’s mind as he formulated his own position, and while there is no doubt that none of Berkeley’s major works would have existed in their present form had Locke never published the Essay, Berkeley would have insisted that much more was at stake than whether Locke got things right. He targeted certain views and assumptions that were very widely held. Thus Locke is the only philosopher he actually identifies and quotes from in the attack on abstract ideas, but even there he sees himself as opposing, not simply some quirky view of Locke’s, but one which, as he put it in a letter, ‘Mr. Locke held in common with the Schoolmen, and I think all other philosophers’ ( Works , vol. 2: 293). These certainly included Malebranche, for example, who, Berkeley elsewhere complained, ‘builds on the most abstract general ideas’ (Works, vol. 2: 214). Again, when he says that ‘Some there are who make a distinction betwixt primary and secondary qualities’ (Principles §9), he really does mean ‘some’, and not just Locke; and the same could be said of his opposition to the notion of ‘material substance’. In short, Berkeley often had his eye on other thinkers too, and some of these must also count as influences. As is now widely recognized, these included writers in the Cartesian tradition, most notably Malebranche but also probably Pierre Bayle.

The relationship between Berkeley and Descartes is interesting – after all, it was Descartes who had introduced a radical dualism of ‘matter’ and ‘mind’, and although Berkeley rejected matter, he adhered to a broadly Cartesian view of the mind (see Dualism). However, Malebranche is particularly important in the story, both because Berkeley had studied his De la recherche de la vérité at an early stage, and because Berkeley’s position struck many as remarkably close to that of Malebranche. In particular, Berkeley positively denies the existence of bodies ‘without the mind’, but Malebranche had already argued that it was impossible to prove their existence conclusively, thus paving the way for their dismissal. Again, Malebranche had insisted that there are no corporeal causes, and that, strictly speaking, God is the only cause, and Berkeley certainly holds that only spirits can act. Moreover, Malebranche held, and Berkeley at least suggested, that in perception, God’s ideas are revealed to us. It is significant, then, that in his own day, despite his protestations, Berkeley was often seen as essentially a follower of Malebranche. We might note, finally, that while Malebranche had concluded that neither sense nor reason could conclusively establish the existence of bodies, he also held that faith in the Scriptures did require this belief. When in the Principles Berkeley considers a number of possible objections to his positive rejection of ‘matter’, this argument from the Scriptures is the last that he chooses to tackle. As he says, ‘I do not think, that either what philosophers call matter, or the existence of objects without the mind, is any where mentioned in Scripture’ ( Principles §82).

There is evidence that Bayle too was an early influence, and when, as in the preface to the Principles, Berkeley refers to ‘those who are tainted with scepticism’, arguments he found in Bayle’s Dictionnaire historique et critique were probably towards the front of his mind. Bayle had offered arguments against regarding extension and motion as any more objective than colour or smell (which the Cartesians recognized as mere ‘sensations’), and for the view that the notion of real extension (for Cartesians the essence of matter) involved contradictions. Strict reasoning, Bayle argued, would thus lead us to deny the existence of bodies, in the face of our (fortunately) ineradicable beliefs. Berkeley could welcome and adapt these arguments to the extent that he was concerned to reject bodies ‘without the mind’, and while, unlike Bayle, Berkeley firmly denied that they lead to scepticism or to any conflict with common sense, it is hardly surprising if many of his contemporaries took a different view. As Andrew Baxter saw it, Berkeley was committed to the conclusion that ‘he has neither country nor parents, nor any material body (but that all these things are mere illusions, and have no existence but in the fancy’ ( Baxter [1733] 1737 , vol. 2: 260).

3 Berkeley’s metaphysics

Berkeley is understandably best known for his (at first sight outrageous) claim that mind or spirit is the only substance, and that it is God who produces ‘sensations’ or ‘ideas’ in our minds. From the beginning, many regarded this view as sceptical at best or insane at worst, and Berkeley recognized that this might be the initial reaction. It is, then, an important feature of his position that, if rightly understood, his standpoint will be seen as common sense, and in accord with the views of the unsophisticated ‘vulgar’. The purpose of the present section is to sketch in very general terms how Berkeley could see things in this way.

To begin with, we can hardly make sense of Berkeley’s position unless we see him as starting from an assumption that he took both to be obviously true and to be shared by other philosophers, which was that each of us is aware only of the ‘ideas’, ‘sensations’ or ‘perceptions’ that are somehow or other produced in our minds. On the most common view – that taken by Descartes and Locke for example – these are produced in us by external objects, which objects we do not perceive ‘immediately’ because, as Locke put it (whatever precisely he meant by it), ‘the Mind… perceives nothing but its own Ideas’ (Locke, Essay IV 4: §3). Berkeley’s first insight, and it is one that his reading of Malebranche and Bayle must have encouraged, was that if we set things up in this way – distinguishing between the ‘ideas’ we perceive and the ‘real’ objects which lie hidden beyond them – scepticism becomes inevitable. At best we can hypothesize the existence of ‘real’ objects as the most likely causes of our ideas, but then we are vulnerable to the suggestion that there could be other causes, including, most plausibly, God. There are other difficulties too. Berkeley found it widely admitted that it is quite unclear how inert ‘matter’ could act on minds so as to produce ideas or perceptions in them (and Malebranche and other ‘occasionalists’ had denied that it in fact does) (see Occasionalism ); moreover, Berkeley found only obscurities and incoherencies in the prevalent conceptions of ‘material substance’. Yet the most fundamental insight was to follow.

This insight was that when we – ordinary men and women – talk of houses, mountains, rivers and so on, we are talking about what we experience or are aware of, not of occult objects that we are not directly aware of at all. It follows, or at least it seemed to Berkeley to follow, that if when we refer to houses, mountains and rivers we are referring to things we are aware of, and if (as other philosophers agreed) we are aware only of ideas, houses, mountains and rivers must be ‘ideas’ or appearances or, better, ‘collections’ of such ideas. Certainly – and this was one thing that his readers found most difficult to handle, but which Berkeley himself was most insistent on – there is no need to deny that houses, mountains and rivers exist, but only to stress (common-sensibly) that they are the very things we perceive, which is to say that they are mind-dependent ideas. Their esse (being) is percipi (to be perceived); they exist only in the mind.

Berkeley’s major philosophical works, and in particular the Principles and Dialogues, are, in the main, a sustained defence of these insights and doctrines, together with a working out of their implications. For Berkeley, the implications, including those for religion and the sciences, are as important as the basic metaphysics. Yet the fundamental case for that metaphysics is supposed to be very simple indeed. Even by the end of section six of the Principles (under three pages in most editions) that case has supposedly been established.

4 The New Theory of Vision

Although Berkeley’s An Essay towards a New Theory of Vision (1709) was published just one year before the Principles, and Berkeley was already convinced that there was no such thing as ‘matter’, or bodies ‘without the mind’, this, his first major work, stopped short of making that claim. As he said in the Principles, although the earlier book had shown that ‘the proper objects of sight neither exist without the mind, nor are the images of external things ( Principles §44; emphasis added), it had done nothing to disabuse readers of the view that tangible objects are external. At one level, then, the work can be seen as a sort of halfway house on the route to presenting his full case for immaterialism, but it is undoubtedly also true that he was fascinated by problems concerning vision in their own right. He was clearly very well read in optical theory, he had his own highly distinctive contribution to make, and for many years that contribution was esteemed by many who had little interest in, or were possibly quite blind to, any wider implications it may have had.

Ostensibly, then, the New Theory of Vision is merely an attempt to ‘shew the manner wherein we perceive by sight the distance, magnitude, and situation of objects’, though, still in the opening section, Berkeley also announces that he will be considering ‘the difference there is betwixt the ideas of sight and touch, and whether there be any idea common to both senses’ (New Theory of Vision §1). Broadly, the issue concerning ‘situation’, which others had recognized, is that of how we see things the ‘right’ way up (so to speak) when their images are inverted on the retina; that concerning ‘magnitude’ is how we judge objects at a distance to be small or large (one particular problem was why the moon on the horizon looks larger than the moon in the zenith, although they are virtually the same distance from us); and that concerning ‘outness’ or distance is that of how we come to see things as being at various distances, given that, as Berkeley observes, it was accepted that ‘distance being a line directed end-wise to the eye, it projects only one point in the fund of the eye, which point remains invariably the same, whether the distance be longer or shorter’ ( New Theory of Vision §2). Berkeley’s solution is similar in each case. In the case of distance, for example, even when an object is relatively close, we do not, as others had supposed, make our judgments on the basis of what Descartes had described as a sort of ‘natural geometry’, and on facts such as that lines drawn from the two eyes to the object form a greater angle the closer the object is: the supposed lines and angles are only theoretical entities, and are not at any rate perceived. Rather, we learn to make these judgments solely on the strength of certain sensory cues including, for example, the sensations accompanying the turn of the eyes, and the increasingly confused appearance of an object as it comes closer to us. An explanation in terms of geometry is thus replaced by a psychology of vision in which, crucially, the connection between the cues and the distance discoverable by touch turns out to be purely contingent. ‘[I]f it had been the ordinary course of Nature that the farther off an object were placed, the more confused it should appear, it is certain the very same perception that now makes us think an object approaches would then have made us to imagine it went farther off’ ( New Theory of Vision §26).

Though often regarded as controversial, Berkeley’s work on the psychology of vision was also highly influential even though, and indeed partly because, Berkeley’s ultimate metaphysical commitments are not apparent, and certainly not necessarily required for an acceptance, for example, that ‘a man born blind, being made to see, would at first have no idea of distance by sight’. Admittedly Berkeley’s account of our judgments is in terms of ‘sensations’, ‘appearances’ and ‘ideas’, as all we have to go on, and we are told, for example, not only that the man just cured of blindness would take the ‘objects intromitted by sight’ to be ‘no other than a new set of thoughts or sensations, each whereof is as near to him as the perceptions of pain or pleasure, or the most inward passions of his soul’, but that he would be right to do so ( New Theory of Vision §41). Yet nothing is said to disabuse the reader of the thought that there is, for example, a distant moon, which is not at all dependent on the mind. There is a sense, therefore, in which the New Theory of Vision offers us some of the fruits of idealism without explicitly announcing the immaterialism, and one of those fruits is an indication of the existence of God (see Idealism). By the end of the work, Berkeley has concluded that there are no ideas common to sight and touch: the extension perceived by touch, for example, is quite distinct from, and has no likeness to, any visual idea. Here he considers a problem first raised by William Molyneux and discussed by Locke, agreeing with them that a man just cured of blindness who saw a cube and a globe for the first time would not know just by looking which was which, but seeing this answer as confirming his own view that visual ideas are merely ‘signs’. These we learn to correlate with tangible ideas in much the same way as we learn a language. Berkeley takes this analogy very seriously. His conclusion in the first edition is thus that ‘the proper objects of vision constitute the universal language of nature, whereby we are instructed how to regulate our actions’, but by the third edition ‘nature’ has become ‘the Author of nature’, or God ( New Theory of Vision §147).

5 The Introduction to the Principles

Berkeley prefaces A Treatise concerning the Principles of Human Knowledge (1710) with an important introduction which is for the most part devoted to an attack on abstract ideas, and in particular abstract general ideas. In it he quotes freely from Locke. Yet, as already stated, his target was wider, including philosophers generally and, ultimately, a variety of philosophical confusions. One needs to look outside the introduction to discover what these alleged confusions are. Sometimes this is fairly straightforward. Even in the New Theory of Vision the notion that there is an idea of extension common to both sight and touch is ascribed to the supposition that we can abstract it from all other visible and tangible qualities; while, in the Principles, the notion that the supposed ‘primary’ qualities exist in the outward object, although colours and the like are ‘in the mind alone’, is undermined by the observation that ‘extension, figure, and motion, abstracted from all other qualities, are inconceivable’. Similarly, the idea of ‘pure’ or ‘absolute’ space is ruled out, it being ‘a most abstract idea’. In one important case the connection is perhaps less obvious: Berkeley claims that holding that sensible objects can exist unperceived depends on illegitimate abstraction, but commentators have often found it difficult to see precisely how this is supposed to work. In yet other cases, the supposed connections have been less frequently explored in the literature, as for example when Berkeley has it that the Schoolmen were ‘masters of abstraction’ and, in the Dialogues , that Malebranche ‘builds on the most abstract general ideas’. These matters can probably be sorted out. Malebranche had attacked the ‘disordered abstractions’ of the Schoolmen, who posited occult qualities and powers, and who supposed that matter is something distinct from its known attributes, and in particular from extension, and Berkeley had probably learned from that. Yet Malebranche himself fell foul of Berkeley’s anti- abstractionism by talking of ‘absolute’ and ‘intelligible’ extension, by supposing that extension was the essence of matter, and by assuming an idea of ‘being in general’. The connection between abstraction and the denial of the ‘esse is percipi’ principle is trickier.

Berkeley’s introduction attacks the view that, although the qualities of objects are always ‘blended together’ in them, we can frame a separate idea of each quality; that we can form, for example, an abstract idea of colour or extension in general; and that we can frame an idea corresponding to the word ‘man’ or ‘triangle’, as distinct from the ideas of particular men or particular triangles, as Locke had suggested. This in turn requires from Berkeley an alternative account of language to Locke’s, which will not require that each general term stands for an idea. This alternative account is not worked out very fully, but Berkeley does insist that ‘a word becomes general by being made the sign, not of an abstract general idea but, of several particular ideas, any one of which it indifferently suggests to the mind’ ( Principles, Intro. §11). Moreover, suggestions towards the end of the introduction that words have other uses than to mark out ideas, including the production of appropriate emotions – ‘May we not, for example, be affected with the promise of a good thing, though we have not an idea of what it is?’ ( Principles, Intro. §20) – have rightly been seen as significant, and further developments along these lines, in particular in the seventh dialogue of Alciphron, have even been seen as making him a precursor of Wittgenstein in this area.

6 The Principles

Berkeley’s basic metaphysical position is usually known as ‘idealism’ or, because of what it denies, as ‘immaterialism’, and the classic defence of this position is offered in A Treatise Concerning the Principles of Human Knowledge . Like all Berkeley’s works, this is well structured, with just 156 short sections: sections 1–33 argue the case for his idealism, sections 34–84 anticipate and answer possible objections, and the remaining sections take ‘a view of our tenets in their consequences’.

As already indicated, Berkeley takes even his opponents to accept that, whatever else there may turn out to be in the world, we perceive only ideas. This assumption emerges in the opening section of the Principles (which is clearly modelled on the opening sections of the first chapter of Book II of Locke’s Essay ). Here Berkeley writes, or at least suggests, that ‘the objects of human knowledge’ are all ‘ideas’, adding that when certain ideas, for example a certain colour, smell and so on, are found going together they are ‘reputed as one thing’. On the face of it, this blurs Locke’s distinction between ‘qualities’ and ‘ideas’, and ignores Locke’s supposition of a ‘substratum’ for the qualities. Yet Berkeley knows what he is doing, and clearly found encouragement in Locke’s own preparedness not only to use ‘idea’ where he means ‘quality’, but also to assert that we have no other ideas of particular sorts of substances ‘than that which is framed by a collection of those simple ideas which are to be found in them’. Certainly, we are supposed to start with ‘ideas’, although – as Berkeley points out in the second section –there are also the minds or spirits that perceive them. However, he soon insists that there can be no substance apart from mind. Given that sensible objects are ideas, and that ideas exist only when perceived, it becomes simply absurd to suppose that these objects could have any existence apart from perception; a fact that is confirmed, in Berkeley’s view, simply by attending to ‘what is meant by the term exist when applied to sensible things’. When I say that a table ‘exists’, I am referring to something that I perceive, or at least that I might perceive, and certainly not applying ‘exists’ to some object which, because it is not an idea, is not perceived at all.

This argument, like most of Berkeley’s arguments, is tricky and needs careful handling. Ostensibly, it seems to have very little to do with the word ‘exists’ because, as Andrew Baxter observed, neither philosophers nor ordinary people seem to mean ‘is perceived’ by ‘exists’ in sentences such as ‘the table exists’. That point is a fair one, and Berkeley’s actual argument does seem to depend heavily on the underlying assumption that the only perceivable objects are mind-dependent items, which must consequently be actually perceived. The stress put on the word ‘exists’ remains puzzling, however, and one relevant fact seems to be that Locke had held that ‘existence’ was a simple idea ‘suggested to the Understanding, by every Object without, and every Idea within’ (Locke, Essay , II 7: §7). Berkeley had convinced himself both that the idea thus described was abstract (and hence impossible), and that this idea is involved when people suppose things to exist quite independently of perception. To perceive a table as existing and to simply perceive it are one and the same experience, and the existence cannot be separated from the perception so that we can attribute an ‘absolute existence’ to the thing.

That is at any rate what Berkeley concludes on the basis of the first few sections. But of course he expected resistance. His tactic now becomes, therefore, to seize on supposedly unsatisfactory features of his opponents’ position and, by exposing them, to further his own case. If it is suggested, for example, that our ideas are merely the likenesses of external qualities, the counter is that an idea (or perceived thing) can be like nothing but an idea (or another perceivable thing). To those who argue that the supposed ‘primary’ qualities exist in outward objects but that colours and the like do not, his response is twofold: first, we cannot even conceive of an object having merely extension, figure and motion, but lacking any of the qualities these other philosophers recognize as mind-dependent; second, the basic argument deployed to prove that secondary qualities are mind-dependent (that is, that the appearance varies in varying circumstances) would prove the same of any quality whatsoever. Furthermore, those who posit a material substratum as the support of qualities find that they can attach no clear meaning in this context even to the term ‘support’. There are other arguments, including a particularly tricky and much discussed one in which he proudly claims that it is impossible to conceive that there even might be a mind-independent object, for to conceive it would be to frame the idea of it, which would mean that it was an object of thought or perception after all. However, Berkeley is at his rumbustious best in sections 18–20, arguing that neither sense nor reason can establish that there are external bodies, and that they cannot even be posited as an hypothesis to account for our receiving the ideas we do. Even if we suppose, arbitrarily, that there are external bodies, the materialists ‘by their own confession are never the nearer knowing how our ideas are produced: since they own themselves unable to comprehend in what manner body can act upon spirit, or how it is possible it should imprint any idea in the mind’ ( Principles §19). What emerges, predictably, is that the only possible cause of our ideas is another, superior spirit, who presents our ideas to us in orderly ways which in fact constitute the Laws of Nature, and which Berkeley also sees as constituting the language of God himself.

7 The Principles (cont.)

While the first thirty-three sections of the Principles are in an obvious sense basic, the sections in which Berkeley deals with possible objections to his thesis are important too. Here most readers new to Berkeley are likely to find that the first objections that spring to their minds have been anticipated, while the answers Berkeley gives help to clarify his basic thesis. The objections he envisages include, for example, that, given his idealism, everything becomes illusory or unreal; that we see things at a distance from us, so they are not ‘in the mind’; that, if the esse of sensible things is percipi, they will disappear when we stop perceiving them, which is absurd; and that, if objects are only ideas, or collections of ideas, there can be no causal interaction between them, so we will have to deny that fire heats and that water cools. Whether Berkeley’s answers to such objections satisfy us is another matter, but the objections are at least confronted, and the answers are always interesting. On the third objection mentioned above, for example, it is eventually suggested that for an object to exist it is necessary only for some mind to perceive it, with the implication that God’s perception may guarantee the continued existence of objects. The answer to the fourth objection above is that, just as we continue to say that the sun ‘rises’ despite scientific knowledge that it is the earth that moves, so this is another area where ‘we ought to think with the learned, and speak with the vulgar’ ( Principles §51), recognizing that, strictly, the regularities in nature we describe as causal are ultimately down to God. In answering both these objections, Berkeley is typically quick to point out that his philosophical opponents are insecurely placed to make them. Even those who hold that there are external and material bodies are committed to the view that light and colours, or visible objects, are ‘mere sensations’, and thus to holding that these disappear when I shut my eyes; while, when it comes to causal relationships between objects, many other philosophers, both among the Schoolmen and modern philosophers, have held that God is the ‘immediate efficient cause of all things’.

In answering the second of the above objections, Berkeley predictably refers the reader back to the New Theory of Vision; but his answer to the first objection is more complex. There are, he stresses, decisive differences between the ‘faint, weak, and unsteady’ ideas of the imagination and those imprinted on the senses by God, and though he calls both ‘ideas’ to emphasize that they are equally in the mind, he would not object to simply calling the latter ‘things’. Nor does he deny even that there are corporeal substances, if ‘substance’ is taken ‘in the vulgar sense, for a combination of sensible qualities’. It is, he suggests, only other philosophers he opposes, for they take corporeal substance to be ‘the support of accidents or qualities without the mind’. We may well feel that this point glosses over the one big difference between Berkeley and the vulgar, which is that the vulgar do not recognize sensible qualities to be mind- dependent ideas, but it is one that Berkeley insists on. ‘The only thing whose existence we deny, is that which philosophers call matter or corporeal substance. And in doing of this, there is no damage done to the rest of mankind, who, I dare say, will never miss it’ ( Principles §35).

8 The Principles (cont.)

The full title of the Principles describes it as a work ‘Wherein the chief causes of error and difficulty in the Sciences, with the grounds of Scepticism, Atheism, and Irreligion, are inquired into’. While Berkeley believes idealism to be true, he is as interested in the benefits that flow from accepting it. These include establishing the existence of God and attaining a proper understanding of God’s role in the world; the banishment of scepticism concerning the nature and the very existence of ‘real’ things, both of which result from distinguishing the ‘real’ from what we perceive; and the resolution of certain philosophical, scientific and mathematical perplexities. From section 85 onwards, therefore, Berkeley takes ‘a view of our tenets in their consequences’.

Some of the supposed advantages are obvious once stated, and they include the resolution of three issues Berkeley mentions at the outset: ‘Whether corporeal substance can think?’ (a possibility mooted by Locke, which threatened belief in the natural immortality of the soul); ‘Whether matter be infinitely divisible?’ (a long- standing issue, with Bayle in particular having exposed the paradoxes that arise whether we suppose that it is or it is not); and ‘how [matter] operates on spirit?’ (a problem that had exercised the Cartesians). None of these questions arises once it has been proved that there is no ‘matter’; that the soul is immaterial, or ‘one simple, undivided, active being’ which is therefore ‘indissoluble by the force of Nature’; and that, just as we can produce ideas in our own minds when exercising our fancies, so God (the superior spirit) can produce in our minds those ideas which constitute sensible things. In addition, however, Berkeley explores at some length the implications for natural philosophy and mathematics.

These, it must be stressed, were not simply casual interests for Berkeley. His very first publication – a compilation of two titles, Arithmetica and Miscellanea Mathematica, (1707) – evidences his early proficiency in mathematics, and the philosophically more significant manuscript Of Infinites was written at about the same time. The latter concentrates on the ‘disputes and scruples’ which infect modern analytical geometry, all arising from ‘the use that is made of quantitys infinitely small’. Moreover De Motu (1721) includes an examination of the role that such concepts as force, gravitation and attraction play in Newtonian mechanics. There would have been more on these topics in the additional parts of the Principles which Berkeley intended to write, as indeed there would have been on persons, perceivers or spirits. What he does say on the latter subject in the Principles as we have it is thin, and it is perhaps necessary only to note that Berkeley’s view is indeed broadly Cartesian, though the Berkeleian dualism is between ‘indivisible, incorporeal, unextended’ minds and ideas, not minds and ‘matter’; that he even convinces himself that the soul always thinks; and that the stress is on Berkeley’s claim that we do not know ourselves, or other spirits, by way of idea. This insistence underlies our earlier observation that in the opening section of the Principles Berkeley writes, or at least suggests, that all the objects of knowledge are ideas; for the truth is that, though Berkeley was prepared to give this impression at the outset (presumably so as not to raise an unnecessary complication early on), his own use of ‘idea’ for ‘any sensible or imaginable thing’, as he put it in the Philosophical Commentaries, rules out any ‘idea’ of spirit, or of the operations of the mind. Certainly, though, this is not supposed to be worrying, and Berkeley is not suggesting that the word ‘mind’ is insignificant. When he started penning the entries in the Commentaries he had indeed accepted the Lockian view that all significant words stand for ideas, but he had soon rejected that principle, partly as a result of deciding that the essentially active mind must be carefully distinguished from its passive objects or ‘ideas’.

9 Three Dialogues between Hylas and Philonous

The Principles of Human Knowledge is the most important book in the Berkeleian corpus and, had its reception not been so disappointing to Berkeley, the Three Dialogues between Hylas and Philonous (1713) would probably not have been written. People were readier to ridicule than to read a treatise that denied the existence of ‘matter’, while those who did read it usually misunderstood it. The Dialogues, therefore, were written, as Berkeley says in the preface,‘to treat more clearly and fully of certain principles laid down in the First [Part of the Principles], and to place them in a new light’, and the dialogue form proved an admirable way of allowing likely objections to be dealt with at each stage (as well as making the book still perhaps the most attractive introduction to Berkeley). The protagonists are Hylas (the name derives from the Greek word for ‘matter’) and Philonous (the ‘lover of mind’, representing Berkeley himself). At the outset Hylas assumes that the Berkeleian is the proponent of ‘the most extravagant opinion that ever entered into the mind of man’ ( Works, vol. 2: 172), but, as the discussion progresses, Philonous is able to demonstrate that, although he accepts with other philosophers that ‘the things immediately perceived, are ideas which exist only in the mind’, his additional acceptance of the view of ordinary men and women that ‘those things they immediately perceive are the real things’ allies him with common sense ( Works , vol. 2: 262).

Doctrinally there are no substantial innovations here, although Berkeley has Philonous take pains early on to convince Hylas that ‘sensible qualities’, or the things immediately perceived, are mind-dependent, making great play of how appearances vary for different perceivers, and for the same perceiver in different circumstances. Other features include a striking passage, expanded in the third edition, which contains an anticipation of, and an attempt to answer, what is normally taken to be the Humean point that material and spiritual substance are on a par, so that if one is rejected, so too should the other. It is indeed a particularly attractive feature of the work that Hylas is allowed to be a quite pugnacious opponent who really does test the idealist’s position. To give just one other instance, it is likely to occur to us that, if the things we perceive are identified with ‘ideas’ or ‘sensations’, surely each idea will be dependent on the particular mind that has or perceives it, with the apparently far from common-sense consequence that ‘no two can see the same thing’. Berkeley’s answer may or (more likely) may not satisfy us, but there is a deeper issue underlying Hylas’ challenge which Berkeley himself may not have adequately explored. This concerns the relationship between particular ideas – whether described as ‘sensations’ or ‘appearances’ – and the ‘collections’ of ideas which, for Berkeley, constitute publicly observable objects. There are no more than hints that Berkeley may be prepared to countenance the notion that the permanently existent table is an archetypal idea in God’s mind, and that we can be said to perceive it when we perceive any of the ‘fleeting… and changeable ideas’ which, to some degree, correspond to it.

10 De Motu

Berkeley intended to publish additional parts of the Principles and apparently made some progress on the second part, telling Samuel Johnson in 1729 that ‘the manuscript was lost about fourteen years ago, during my travels in Italy, and I never had leisure since to do so disagreeable a thing as writing twice on the same subject’, but that was as far as he got. Remarks in the Philosophical Commentaries suggest that one part would have been ‘our Principles of Natural Philosophy’, and we can assume that it would have included the sort of material covered in a work he did publish, De Motu (1721). This work reiterates and develops certain points already made in the Principles when Berkeley was taking ‘a view of our tenets in their consequences’, but although it is indeed assumed that minds are not corporeal, it would not have been apparent to the reader that Berkeley holds that the esse of sensible things is percipi. Rather, what is insisted on is that ‘it is idle to adduce things which are neither evident to the senses, nor intelligible to reason’ (De Motu §21), and that when we attribute gravity and force to bodies we are improperly positing occult qualities which take us beyond anything we can experience or conceive. ‘Abstract terms (however useful they may be in argument) should be discarded in meditation, and the mind should be fixed on the particular and the concrete, that is, on the things themselves’ ( De Motu §4).

It is, therefore, idle to look to the qualities of bodies themselves in order to discover a cause of motion, for ‘what we know in body is agreed not to be the principle of motion’ ( De Motu §24). Relying as we should on what we can conceive, we must look to mind for that principle, for we know from our ability to move our limbs that minds can act. On this basis we should conclude that ‘all the bodies of this mundane system are moved by Almighty Mind according to certain and constant reason’ ( De Motu §32).

It is clear, then, that De Motu fits in with Berkeley’s ultimate aim in all his philosophical writings, which is to bring out the dependence of the world upon God. Yet here, as in the case of everything he was to publish later, the elements of his metaphysics that had most perplexed the readers of the Principles and the Dialogues are either absent or in the background. Indeed, it is a feature of De Motu that Berkeley is anxious to present himself as representing a tradition going back to the ancient Greeks, but including the Schoolmen and the Cartesians, which recognizes the ultimate dependence of motion on God. Indeed, ‘Newton everywhere frankly intimates that not only did motion originate from God, but that still the mundane system is moved by the same actus’ ( De Motu §32). It must be stressed, however, that it is not this supposed consensus that makes Berkeley’s philosophy of science interesting, but his understanding of the proper role of the natural scientist as contrasted with that of the metaphysician. Terms such as ‘gravity’ and ‘force’, for example, have a legitimate use, in facilitating calculations on the basis of certain observable regularities in the behaviour of objects. We go wrong only if we confuse the discovery of regularities with genuine explanations of them. By contrast, absolute space and absolute motion, which were posited in Newtonian mechanics, are rejected outright, as indeed they were in the Principles. We should ‘consider motion as something sensible, or at least imaginable,’ and ‘be content with relative measures’ ( De Motu §66). If there were but one body in the universe, it would make no sense to suppose that it moved (see Newton, I. ).

11 Alciphron and The Analyst

Berkeley published De Motu in 1721 and nothing of any philosophical significance for over ten years thereafter. Indeed none of his later writings matched in importance what had already appeared. Yet all were controversial, and some were taken very seriously at the time. These included Alciphron (1732) and The Analyst (1734) which represent, if in very different ways, Berkeley’s commitment to defending religion against those seeking to undermine it.

Alciphron is composed of seven lively dialogues in which two Christian gentlemen, Euphranor and Crito, defend the religious and Christian standpoint against two ‘free-thinkers’, Alciphron and Lysicles. These are, of course, fictitious characters, but are allowed on occasion to present (or misrepresent, as many have claimed) the views of such actual, though unnamed, figures as the third Earl of Shaftesbury and Bernard Mandeville. Mandeville complained bitterly that his thesis that private vices are public benefits had been totally distorted in Alciphron ; others have said the same of Berkeley’s treatment of Shaftesbury’s ethical theory. For all that, the book remains very readable. It contains, moreover, the only account of free-will published by Berkeley, and also the first explicit linking of the doctrine concerning the heterogeneity of the objects of sight and touch to a proof of the existence of God. Additionally there is a discussion in the Seventh Dialogue of particular interest in that it returns us to the topic of language.

The context is still the acceptability of religion, but at this point the objection from the free-thinker Alciphron is that the Christian religion is ultimately unacceptable, not because it can be shown to be false, but because it is straightforwardly unintelligible, involving, as it does, such meaningless notions as that of ‘grace’. Here Alciphron appeals to the principle that ‘words that suggest no ideas are insignificant’. Consequently this principle, which Berkeley had himself assumed in a demonstration of immaterialism nearly half way through the Commentaries, now becomes his explicit target. He reiterates his objection to abstract ideas, but also stresses the role of words in directing our practices, whether in mathematics and natural science, or in the religious sphere. It has been debated whether or not what we find here marks any decided shift from the line he had taken in the introduction to the Principles, and it is certainly true that Berkeley had long since moved towards the position he adopts here, but the discussion in Alciphron does reflect his mature consideration of the topic. It stresses the use of words as signs which, as he had put it to Samuel Johnson, ‘as often terminate in the will as in the understanding, being employed rather to excite, influence, and direct action, than to produce clear and distinct ideas’ ( Works , vol. 2: 293).

By contrast with Alciphron, the Analyst is a technical work in the philosophy of mathematics, containing criticisms of Newton’s calculus. The adequacy of these criticisms is still debated, but they were sufficiently acute to generate considerable controversy among the mathematicians. To this controversy Berkeley contributed two further works in 1735, A Defence of Free-thinking in Mathematics, and Reasons for not replying to Mr. Walton’s Full Answer. Berkeley’s theological preoccupations are again relevant in this area, for The Analyst was addressed to an unnamed ‘infidel mathematician’, who has generally been identified with Edmund Halley (of Halley’s Comet fame). Halley had been reported as claiming that Christian doctrines were ‘incomprehensible’, and the religion an ‘imposture’. Berkeley is able to take delight in answering that the objection comes ill from a mathematician. He targets what he saw as obscurities and contradictions in the calculus. Some of these result from assuming an increment of infinitesimal value which, without reaching zero, proceeds towards a limit of zero, allowing the analyst to predict the system’s value at a conceptual point at which the increment becomes nothing. A consequence is that these ‘ghosts of departed qualities’ are both used and disregarded in one and the same proof. As already mentioned, Berkeley’s interest in mathematics was of long standing, as was his opposition to infinitesimal quantities. He was able to show how these lead to absurdities in the calculus, and to argue against those who ‘though they shrink at all other mysteries, make no difficulty of their own’. Moreover, he was able to do this without mentioning his own idealist view that, because esse is percipi, the smallest quantity must be what he had earlier called the minimum sensibile, which cannot be divided into parts.

12 Siris

Siris (1744), the last of Berkeley’s writings of any substance, is also in many ways the strangest. His championship of tar-water as a useful remedy against many diseases (and as a possible panacea) is likely to strike us as foolish, though it was to some extent understandable given his apparently successful use of it in his diocese. Moreover, although it was practical experience that had led him to his belief in the virtues of tar-water, Berkeley does go deeply into the explanation of its effectiveness, relying on theories which gave prominence to the role of ‘aether’, or ‘pure invisible fire’, as the vital principle of the corporeal world. Here again we can now see that Berkeley was wrong, although he was able to appeal to authorities, both ancient and modern. Indeed, this readiness to appeal to authorities, or to seek for maximum consensus, extends to the final sections in which his chain of philosophical reflections leads him to focus on God as ‘the First Mover, invisible, incorporeal, unextended, intellectual source of life and being’ (Siris §296). Here themes familiar from the early works re-emerge – including the view that ‘all phenomena are, to speak truly, appearances in the soul or mind’ (Siris §251) and that there are, strictly, no corporeal causes. Yet these are now tied in with what appear to be alien elements. There is a tendency to disparage the senses, and Berkeley’s fascination with the philosophies of the ancients extends to a degree of sympathy for the Platonic Theory of Forms. That said, Berkeley’s eclectic and somewhat hesitant approach in Siris is such that it would be wrong to look to it for evidence of a substantially new philosophical position. Though fascinating in its way, Siris now seems very dated indeed.

13 Concluding Remarks

Inevitably, Berkeley is famed for the metaphysics of the Principles, and Dialogues. It would be easy to multiply quotations from people who treated that metaphysics as absurd, but very wrong to suggest that all the reactions have been hostile, or that the more hostile responses have not frequently been based on misunderstandings. At the other extreme, John Stuart Mill was to refer to Plato, Locke and Kant among others when describing Berkeley as ‘the one of greatest philosophic genius’ (Mill [1871] 1978: 451), while A.A. Luce, the most prominent Berkeley scholar of the twentieth century, held Berkeley’s views to be fundamentally correct, and to coincide with the common-sense view of the world. Even many who would be less effusive have at least seen Berkeley as playing an important role in the history of philosophy, if only as marking one important stage on the route from Locke to Hume, and then to Kant and modern idealism. Certainly, no serious commentators would judge that his views can be easily or simply dismissed, though they would often give very different accounts of what makes him important and interesting. Luce, for example, found the role God has to play in Berkeley’s system attractive; Mill thought it an embarrassment. Phenomenalism, the theory of perception which Mill himself espoused, could indeed be described as ‘Berkeley without God’ (see Mill, J.S. §6; Phenomenalism ).

The fact is that Berkeley was grappling with problems that are perennial in philosophy, including that of the relationship between appearance and reality, or between our experiences and what we take them to be experiences of. Their treatments of these issues have very often led philosophers to say things that would strike the ‘vulgar’ as strange, and if Locke’s position, for example, seems initially more congenial (in that Locke never doubts the existence of a world corresponding to, but distinct from, our ‘ideas’, and treats scepticism in that area as absurd), Berkeley was neither the first nor the last to see him as, in effect, making knowledge of that world impossible. Berkeley did not invent the sceptical challenge that arises from insisting on a distinction between what we ‘immediately’ perceive and an external ‘material’ world; if his way of dealing with it is radical, one must recognize that ‘idealism’ in one form or another was to have quite a history – even now there are philosophers who are happy to use the label to describe their own philosophical positions.

Certainly Berkeley does sometimes exaggerate the extent to which he is at one with the ‘vulgar’, or with our ordinary views about the world. He may be quite right that he is at one with those who believe that ‘those things they immediately perceive are the real things’. Yet, as we saw in §9 above, it is only by combining this with the claim that ‘the things immediately perceived, are ideas which exist only in the mind’, which he attributes to ‘the philosophers’, that he arrives at a theory concerning the nature of reality that is very much his own. Consequently, although he can chide his opponents for their commitment to such views as that ‘the Wall is not white, the fire is not hot’, remarking in the Commentaries (entry 392) that ‘We Irish men cannot attain to these truths’, many of his own claims, such as that ‘Strictly speaking… we do not see the same object that we feel; neither is the same object perceived by the microscope, which was by the naked eye’ ( Works , vol. 2: 245), would strike the vulgar as equally odd. Berkeley’s beliefs about what it is that we ‘immediately’ perceive may or may not be true, but clearly they are not vulgar views.

To be fair, Berkeley was not unaware that this was the position. For example, his comment that on the issue of causal relationships between objects we should ‘think with the learned, and speak with the vulgar’ (Principles §51) suggests that the vulgar have not appreciated the truth of the matter; while claims that he opposes only other philosophers contrast with passages such as that in the Principles in which he actually refers to the ‘mistake’ of the vulgar who believe that the ‘objects of perception [have] an existence independent of, and without the mind’ (Principles §56). To be sure, in the same discussion he suggests that they cannot really believe this, because the supposed belief involves a contradiction, and ‘Strictly speaking, to believe that which involves a contradiction, or has no meaning in it, is impossible’ (Principles §54), but the whole passage rests on the equation of the objects of perception with ‘ideas’, which is what makes the supposed belief contradictory.

The truth is, therefore, that for all his resolve in the Commentaries (entry 751) ‘To be eternally banishing Metaphisics &c & recalling Men to Common Sense’ (and what he seems to have in mind there is the arid metaphysics of the Schools), Berkeley does offer us what we would naturally describe as a metaphysics, and one that cannot be refuted simply on the ground that it might strike the average person as outrageous. His arguments must be examined on their merits, together with any underlying assumptions; attention has to be paid to the notion of ‘immediate’ perception which he works with; and account must be taken of possible problems generated by his metaphysical conclusions. These may include, as has often been claimed, an unrecognized tendency towards solipsism. Not that it is necessary to reject or accept his philosophy in total, for there may be insights alongside what we believe are mistakes. As with any philosopher of Berkeley’s stature, doing justice to Berkeley’s philosophy turns out to be a very complex, but also a rewarding exercise, which is why his philosophy still exercises the commentators today.