Born near Dysert in
County Kilkenny, Ireland, the son of an army officer, George Berkeley was
educated at Kilkenny College and Trinity College Dublin, where he studied
mathematics and philosophy. He graduated
B.A in 1700, was elected a Fellow of Trinity in 1707, and taught there (with
various breaks abroad, particularly in Italy) until 1724 when he was made Dean
of Derry (having been ordained in the Church of Ireland in 1710). In 1728 he went to America with a view to
establishing a college in Bermuda but returned In 1731, the promised funding
not having materialized. He was
appointed Bishop of Cloyne in 1734. In
1752 he moved to Oxford, where he died.
PHILOSOPHY OF LANGUAGE/ MATHEMATICS
 "We must beware of being misled by terms
we do not rightly understand", Berkeley wrote [De Motu, 1]. Failure to think about the meanings of the words we use in
philosophical discussion leads to difficulties and errors when we attempt to
define them [Philosophical
Commentaries, vol. I, passim]. We are too ready to accept
conventional meanings. Some words seem
to defy definition. In other cases we
use words which do not have a meaning at all, in that they do not refer to
anything. "All significant words stand for ideas" [Phil Comm., 378] [a]. An
example is Locke's use of the phrase 'material substance' if by this he means
anything other than our actual sense-experiences [see also Principles, I, 17]. Berkeley therefore exhorts us to examine
carefully the way we use our language to analyse it, if we are not to be
misled. So why do we use language? [Principles, Introd., 20ff.]. We use it
for communication. But Berkeley says it is also
used to "raise passions", excite people to action, or deter them from it, and
so on. We therefore need to take account
of these different
functions of language [b] if we are to distinguish between controversies which
are "purely verbal' and others which are not [ibid. 22]. As he says, many
of the difficulties we encounter in philosophy are our own fault: "We have first raised a dust, and then
complain we cannot see" [ibid.
31]. This is particularly evident in our (mis)use of language [c]. Berkeley's view of language underlies his attack on Locke's 'abstract general ideas' [ibid. 6-18]. He supposes Locke to be
saying that we can have ideas (that is, images) not only of equilateral
triangles, right-angled triangles, and so on, but also an idea of a triangle
which is both all and none of these at the same time a claim that Berkeley
rejects. We may use the phrase 'abstract
general idea', but it has no reference or denotatum: it does not 'signify'. However, he does not reject general ideas as
such, only the view that any general name has "one precise and definite
signification" . General words like
'material substance', 'triangle' are not proper names (which signify particular
things). So what are general ideas? According to Berkeley a general word
"signifies indifferently a great number of particular ideas" [ibid.] By this he means that, say, 'triangle' may
refer to this triangle or that
triangle, but not to a 'general triangle' or triangularity. A particular idea "becomes general by being made to represent or stand
for all other particular ideas of the same sort" 12]. Therein lies its universality [c].
Although Berkeley held that words stand
for ideas, he said that there are no ideas of number denoted by the names of
numerals. Number is to be defined as a
collection of units [Principles 120]. In arithmetic we should therefore
consider not 'things' but signs and only to the extent that they "direct us how to act with relation to
things" the operations of arithmetic being as it were a shorthand method of
computation in accordance with rules and which take the place of writing down
successions of individual strokes [ibid.
121]. Signs, he said [Philosoph. Commentaries I, pp. 732-5]
"are perfectly arbitrary and in our power made at pleasure". He later extended this view of arithmetic to
geometry [see De Motu] (having
previously supposed geometry to be about actual lines and figures). Berkeley's approach to mathematics is generally regarded as a conventionalist theory [d].
 In his early Essay towards a New Theory of Vision Berkeley offers an account of how we perceive
distance. He disagrees with the
contemporary 'geometrical' explanation that we estimate distances by
means of measurements of lines and angles, which he says is not supported by
experience [Essay, 12]. Instead he relates perception of
distance to the varying sensations we have when we move towards or away from
some object as a result of the changing "interval
between the pupils" of our eyes ; and also to the degree of "confusion"
in our vision (to avoid which we strain our eyes). There thus arises an association, "a habitual
connexion", between our experience of sensations and distances [21-28]. Distance is "mediated" by an idea we perceive in seeing .
What of the size of sensible objects? Berkeley distinguishes [54ff.] between visible objects and tangible objects,
each kind having its own "distinct magnitude". Consider the moon (67-74]. While
we suppose the actual magnitude of the moon outside us does not change, its
visible apparent size does. How do we
account for this seeming contradiction? Berkeley says that this is because when we see the moon at a distance we
refer its extension to the tangible and not visible magnitude, though the
former may be suggested initially by the latter. He goes on to say that there is no idea in common
between the two senses of sight and touch. Nevertheless there is a correlation between them which he attributes to
"the author of nature" [a]. The proper
objects of vision are, he says, the author of nature's "universal language",
and they signify objects at a distance in the same way that signs of our human
language suggest things through habitual connections and not by likeness of
seems to be suggesting that tangible objects exist outside the mind, while the
visible objects which signify them are 'in' the mind. But in his developed theory of perception [Principles of Human Knowledge] he argues that all sensible objects are 'in'
the mind. His thesis is as follows. What do we mean when we say that a sensible
thing, say, a table exists? Berkeley
says that we see it and feel it, and that if we were out of the room, to say it
existed would be to say we might perceive it on our return (or that some spirit
was actually perceiving it) . To exist, therefore, is to perceive or be perceived [esse est aut percipi aut percipere]. He considers himself to be providing an
analysis of statements about the existence of things which is essentially that
of "vulgar opinion" (the ordinary man's view ) [3-41. Now, the "objects of human knowledge" for Berkeley are ideas. They are either (1) imprinted on the senses; (2) "perceived by attending to the
passions and operations of the mind"; or (3) formed, compounded in memory or by
imagination . He thus rejects the 'innate'
ideas of rationalism [b]. To support this identification of sensible
things with "collections of ideas" he criticizes Locke's distinction between primary and secondary qualities [9-10]. It is not possible to conceive of them as apart from each
other [c]. Qualities such as shape or
extension are just as relative to the perceiver as are colours and tastes. Moreover extension, motion, and so on are
"abstract ideas", which have no signification . Similarly there can be no such entity as a material substratum (the phrase "supporting accidents" has no
sense). (Indeed Berkeley regards the
concept of matter as both unintelligible and pernicious in so far as he considers materialist
philosophies as threatening religion [d].) It follows that sensible things are to be
understood as collections of ideas in the mind [see also Dialogues I].
Does this mean that things do not really
exist outside us even tangibly? In
reply [33- 40] Berkeley says that sensible things as ideas are the real things, but that they exist in a
mind [e]. It might perhaps have
been better, he says, had he not used the word 'idea' and kept to 'thing'. He did so because 'thing' is generally
supposed to denote an entity existing "without" the mind. We might think it "very harsh" to say we eat
and drink ideas, and are clothed with them, but this is simply because the
philosophical language is not familiar; it does not affect the truth. If ideas were distinct, this would lead to universal scepticism because our knowledge would
be confined to our own ideas [Phil. Comms]. A second reason for using 'idea' is that
'thing' includes not only ideas but also spirits or thinking things, and these
are not ideas; rather they have them. Is
there then no distinction between the real and the imaginary? Berkeley's answer to this is that while
'real' ideas are imprinted on our senses by the author of our nature, images of
things (for example, a unicorn) are under our own control; we can choose to
form them at will. Ideas which are real things are also
stronger, more orderly, and more coherent than the creatures of (our own) mind
and less dependent on the spirit which perceives them .
What of that which is perceiving (the percipi not the percipere)? The perceiver for Berkeley is a spirit. We have no idea of such an entity, but Berkeley allows we may have a 'notion'
of it . And he says we can have immediate knowledge
of spirits: of our own by "inward
feeling or reflexion"; and of others (finite human spirits, or the infinite
spirit God) through reason  [f], but only mediately
via the intervention of ideas as "effects or concomitant signs" .
METAPHYSICS/ RELIGIOUS PHILOSOPHY/ ETHICS/ POLITICAL
 Berkeley has distinguished between
collections of ideas and the 'spirits' or minds. What are spirits? A spirit, he says, is "that which thinks,
wills, and perceives" . Now, while
a finite spirit may cease to perceive a table, the collection of ideas
constituting the table remains in existence because they are still being
perceived by God. And indeed he regards
this as the basis for his proof
of God's existence [a]. Sensible things do really
exist. "It is repugnant that they should
subsist by themselves" [Principles 148]. And of course they do not depend for their
existence on our minds. They must
therefore be perceived by an infinite mind, or God [Dialogues II]. Nothing can be more evident, he says
than the existence of God, or a Spirit who is intimately present to our
minds, producing in them all that variety of ideas or sensations, which
continually affect us, on whom we have an absolute and entire dependence, in
short, in whom we live, and move, and have our being.
His argument for the
existence of God thus complements his rejection of a Lockean material 'substratum'.
God is infinite spirit. As for
his general attributes, Berkeley seems to understand them in a limited analogical rather than either an equivocal or univocal sense [Alciphron IV, 16 and 17] [b]; and he says he gets his notion of God by
reflecting on his own soul, heightening its powers, and removing its
imperfections [Dialogues III]. There would appear to be a difficulty
concerning the relationship between our perceptions of sensible things and the
perceptions God has of them 'in His mind'. If things remain in being in God when I am not perceiving them, how is
my mind to be differentiated from God's when I do perceive them? Berkeley's solution is to make a distinction between "archetypal
and eternal" existence of things in God's mind and their original "ectypal or
natural" existence in mine [c] [Dialogues III]. It is God who imprints the ideas in me
after the pattern of His own, and relatively to them. It follows that God is
directly responsible for the order of nature. As infinite active spirit he is the ultimate cause of all that
occurs. The whole of nature is a system of signs [Principles 148], a "visual language of
the Creator as a provident Governor" [Alciphron IV, 14]. What we perceive as a regular connection of ideas
is not a relation of cause to effect but a sign to be signified [d] the direct consequence of God's
intervention. The fire is not the cause
of pain but that which warns me of it in advance [Principles 65].
God is the ultimate cause, should we therefore attribute to Him all
responsibility for evil? Berkeley
denies this: he says that apparent evils in nature
considered in the whole system of things
can be seen to be good; while moral evil is the result of our own freedom [Principles, 153] [e]. And in his moral and political philosophy [see Passive Obedience] Berkeley rejects both psychological egoism and moral sense theories,
and advocates a form of utilitarianism self-love being his principle of
action. By following definite rules
which are laid down by God (and which can be revealed to us through our reason)
our individual happiness and the general good of society can be assured (in the
long run) [ibid., 6] [f]. The laws of society should reflect the
general law of nature (the system of such general rules); and thereby a state of anarchy can be
avoided [g] a state in which there is no
politeness, order, or peace [11 and 15]. Berkeley allows that in
certain circumstances, for example, if society's supreme and lawful authority
enjoins us to transgress the moral law, we may resist though we must accept
any consequent penalties [h].
PHILOSOPHY OF SCIENCE
 Berkeley does not develop a philosophy
of science as such, but to the extent that his account of causality can be
regarded as a scientific (rather than theological) explanation of the "order of
nature" it has implications consistent with his views on language. He is critical of the use of words such as 'attraction', 'absolute
space', which many 'mathematical' natural philosophers suppose to stand
for 'occult entities', but which have no explanatory value. Any idea of pure space is relative; we cannot conceive of the idea of
space as separate from body [Principles 116]. (And he argues against the infinite divisibility of extension [a] a notion which, he says, is the source
of a great many geometrical paradoxes [Principles 123]. It is therefore misleading to attempt to
explain a given phenomenon by saying it is 'caused' by, say, attraction,
'force', or 'gravity'. The only true efficient causes
for Berkeley are active spirits; terms such as 'force' or 'effort' are strictly
speaking applicable only to spiritual agencies and are used in science
metaphorically. So what role do
they play in natural science? Berkeley
says they are but mathematical hypotheses which (in
modern terminology) have instrumental value.
We use them to frame mechanical principles, (for example, 'action and reaction
are equal and opposite'), from which we may derive "general mechanical theorems
and particular explanations of phenomena" [De
Motu 36]. To talk of cause in science is to say that
one phenomenon (or idea) is always found to follow another and never occurs
without it [b]. Berkeley thus distinguishes between (1) explanations of the "order of
nature" in terms of physics, which describe phenomena and
mathematico-mechanical theories and hypotheses, and (2) explanations which relate to genuine efficient
causality, ultimately attributable to the infinite spiritual agency, God [c].
There has been much
discussion about how Berkeley's philosophy should be characterized. He is a realist in the sense that he accepts
the existence of a real world of tables and chairs, and people, and so on. But to the extent that he rejects matter and
the separation of primary and secondary qualities, and identifies external
things as collections of ideas 'in' a mind he may reasonably be termed an
idealist. (H. M. Bracken sees him as an "Irish Cartesian" in The Irish
Mind, ed. R. Kearney.) He regarded
himself as having 'united' both views
the 'vulgar' opinion that what is immediately perceived are real things, and
the 'philosophical' thesis that the things immediately perceived exist only in
the mind [Dialogue III]. Further, in his theory of knowledge he is an
empiricist, though in so far as he appeals to an infinite mind as the ultimate
support of ideas, he is not a phenomenalist. Perhaps this is the most interesting feature of his philosophy: that it is a generally consistent empiricism
underpinned by theistic metaphysical assumptions. But it does give rise to many interesting
(1) The phrase 'in the mind' is
ambiguous. Berkeley clearly does not
want to say that tables and chairs actually exist in his mind, rather that
ideas are dependent on mind. At the same
time he is espousing a version of direct realism: we perceive tables and chairs
directly as collections of ideas; there are no intermediaries (sensibilia,
sense-data, as they are called today). However, in his usage the term 'idea' still refers both to qualities
(red, hard, etc.) and to objects. Is he
right to reject any separation of objects from our immediate experience?
(2) If objects as collections
of ideas are mind dependent, can finite minds be differentiated from the
infinite mind of God? If not, the
Berkeleyan system falls into pantheism. Berkeley's solution, which makes use of an archetype-ectype distinction
raises difficulties. (a) Are archetypes
Platonic Ideas of which our ideas (dependent on finite minds) are but
copies? When I am no longer perceiving,
the ectype ceases to exist but the archetype continues. What then is the ontological status of the
ectypes which God has put into mind? Moreover, how do the varying ectypes of a particular object in different
individuals'minds relate to the one divine archetype?
(3) Berkeley's account of
causation may perhaps represent an advance on Locke's, in that only spirits can
be causes; things (Berkeley's 'ideas' or Locke's 'material things') have no
causative powers. God, however, is the
ultimate cause. But if he puts all the
ideas into our minds is there any role left for our own individual spiritual
agencies? Points 1, 2, and 3 taken together lead to the problem of freedom and
evil. Is God's interventionism
compatible with the free choice of his creatures?
(4) Clearly (as in the
philosophy of Descartes) God's role is crucial. The need for an infinite being to support the continued existence of
objects when they are not being perceived by finite minds is obvious. But for a strict proof Berkeley seems to
appeal only to considerations of teleology and design neither of which is
convincing. Certainly he has not proved the
existence of the infinite, all wise, perfectly good Christian God (to which of
course he was committed as an Anglican Bishop).
Berkeley: Essay towards a New Theory of Vision (1709); Treatise
concerning the Principles of Human Knowledge (1710); Three
Dialogues between Hylas and Philonous (1713); Philosophical Commentaries (Notebooks). The Essay, Treatise, and Commentaries are contained in the collection of Berkeley's works
edited by M. R. Ayers. A selection from
the Essay, the Treatise, and the Three
Dialogues, which also includes extracts from De motu (1721), Alciphron (1732), and Siris (1744), is contained in Berkeley: Philosophical Writings, ed. T. E.
Jessop but now out of print. Note also the essay Passive Obedience or the Christian Doctrine of not Resisting the Supreme
Power, Proved and Vindicated upon the Principles of the Law of Nature (1712), in which Berkeley's views on moral and political philosophy are set
out. (This can be found in the complete
works, edited by A. A. Luce and T. E. Jessop.)
A. A. Luce, Berkeley's Immaterialism: A Commentary on His Treatise concerning the
Principles of Human Knowledge.
J. O. Urmson, Berkeley.
G. J. Warnock, Berkeley.
D. Berman, George
Berkeley: Idealism and the Man.
J. Dancy, Berkeley: An Introduction.
A. C. Grayling, Berkeley: The Central Arguments.
G. Pitcher, Berkeley.
Tipton, Berkeley: The Philosophy of Immaterialism.
J. Foster and H.
Robinson (eds), Essays on Berkeley: A Tercentennial Celebration.
C. B. Martin and D.
M. Armstrong (eds), Locke and
Berkeley: A Collection of Critical
C. Turbayne (ed,), Berkeley: Critical and Interpretative Essays.
K. Winkler, The
Cambridge Companion to Berkeley.