Idealism is any system or theory that maintains that the "real" is of the nature of thought or that the object of external perception consists of ideas. It can also be the tendency to represent things in an ideal form, or as they might or should be rather than as they are, with emphasis on values.
The approach to idealism by Western philosophy has been different from that of East. In Western thought the ideal relates to direct knowledge of subjective mental ideas, or images. It is usually juxtaposed with realism in which the real is said to have absolute existence prior to and independent of our knowledge. Epistemological idealists (such as Kant) might insist that the only things which can be directly known for certain are ideas. In Eastern thought, as reflected in Hindu idealism, the concept of idealism takes on the meaning of higher consciousness, essentially the living consciousness of an all-pervading God, as the basis of all phenomena. A type of Asian idealism is Consciousness-only.
Idealism is often contrasted with materialism, both belonging to the class of monism as opposed to dualism or pluralist ontologies. The contrast between idealism and materialism has to do with the question of the nature of reality.
- 1 History
- 1.1 Idealism in the West
- 1.2 Criticism of Idealism
- 1.3 Idealism in religious thought
- 2 Other uses
- 3 See also
- 4 Notes
- 5 References
- 6 External links
Idealism names a number of philosophical positions with quite different tendencies and implications..
Idealism in the West
In common discussion, Plato is often referred to as an "idealist", because of his doctrine of the "Forms," which are certainly "ideals," in a broad sense. But Plato doesn't describe the Forms as being in any mind. Instead, he regularly describes them as having their own, independent existence. So it seems clear that Plato is not, at any rate, "subjective" idealist, like Berkeley.
Plato's Allegory of the Cave is sometimes interpreted as drawing attention to the problem of knowing "external objects"--the problem that concerned Descartes, Locke, Berkeley, and other modern philosophers. But the Forms that the Cave-dwellers are ignorant of aren't "external" to them in the way that material objects are for these modern thinkers. The Forms are the true realities, but they aren't spatially outside us, as material objects are. So the issue that Plato's allegory addresses--which is, roughly, how can we know what is truly real (and truly good)?--is quite different from the modern issue of our knowledge of the "external world."
However, even if Plato doesn't share the specific concerns of modern philosophy, and of George Berkeley, in particular, Plato could still be a non-subjective idealist. He could believe that matter has no independent existence, or that full "reality" (as distinct from mere existence) is achieved only through thought. Bernard Williams and Myles Burnyeat have maintained that Greek philosophers never conceived of idealism as an option, because they lacked Descartes's conception of an independently existing mind. But Williams and Burnyeat didn't consider the possibility that Plato could have held an idealism like Kant's, which argues from the nature of knowledge to the nature of the objects of knowledge, or like Hegel's, which denies that matter is fully "real"--without (in either case) reducing material objects to ideas in a mind or minds. Moreover, Plato's theory of the separation of soul and body could be seen as an earlier, rougher form of Cartesian dualism.
The German Neo-Kantian scholar, Paul Natorp, argued in his Plato's Theory of Ideas. An Introduction to Idealism (first published in 1903) that Plato was a non-subjective, "transcendental" idealist, somewhat like Kant, and Natorp's thesis has received support from some recent scholars.
Schopenhauer wrote of this Neoplatonist philosopher: "With Plotinus there even appears, probably for the first time in Western philosophy, idealism that had long been current in the East even at that time, for it taught (Enneads, iii, lib. vii, c.10) that the soul has made the world by stepping from eternity into time, with the explanation: 'For there is for this universe no other place than the soul or mind' (neque est alter hujus universi locus quam anima), indeed the ideality of time is expressed in the words: 'We should not accept time outside the soul or mind' (oportet autem nequaquam extra animam tempus accipere)." (Parerga and Paralipomena, Volume I, "Fragments for the History of Philosophy," § 7)
Similarly, professor Ludwig Noiré wrote: "For the first time in Western philosophy we find idealism proper in Plotinus (Enneads, iii, 7, 10), where he says, "The only space or place of the world is the soul," and "Time must not be assumed to exist outside the soul." It is worth noting, however, that like Plato but unlike Schopenhauer and other modern philosophers, Plotinus does not worry about whether or how we can get beyond our ideas in order to know external objects.
Writing about Descartes, Schopenhauer claimed, "...he was the first to bring to our consciousness the problem whereon all philosophy has since mainly turned, namely that of the ideal and the real. This is the question concerning what in our knowledge is objective and what subjective, and hence what eventually is to be ascribed by us to things different from us and what is to be attributed to ourselves." (Parerga and Paralipomena, Vol. I, "Sketch of a History of the Doctrine of the Ideal and the Real") According to Descartes, we really know only what is in our own consciousnesses. We are immediately and directly aware of only our own states of mind. The whole external world is merely an idea or picture in our minds. Therefore, it is possible to doubt the reality of the external world as consisting of real objects. “I think, therefore I am” is the only assertion that can’t be doubted. This is because self-consciousness and thinking are the only things that are unconditionally experienced for certain as being real. In this way, Descartes posed the issue of epistemological idealism, which is awareness of the difference between the world as an ideational mental picture and the world as a system of external objects.
Malebranche, a student of the Cartesian School of Rationalism, disagreed that if the only things that we know for certain are the ideas within our mind, then the existence of the external world would be dubious and known only indirectly. He declared instead that the real external world is actually God. All activity only appears to occur in the external world. In actuality, it is the activity of God. For Malebranche, we directly know internally the ideas in our mind. Externally, we directly know God's operations. This kind of idealism led to the pantheism of Spinoza.
Leibniz expressed a form of Idealism known as Panpsychism in his theory of monads, as exposited in his Monadologie. He held Monads are the true atoms of the universe, and are also entities having perception. The monads are "substantial forms of being" They are indecomposable, individual, subject to their own laws, un-interacting, and each reflecting the entire universe. Monads are centers of force; substance is force, while space, matter, and motion are phenomenal. For Leibniz, there is an exact pre-established harmony or parallel between the world in the minds of the alert monads and the external world of objects. God, who is the central monad, established this harmony and the resulting world is an idea of the monads’ perception. In this way, the external world is ideal in that it is a spiritual phenomenon whose motion is the result of a dynamic force. Space and time are ideal or phenomenal and their form and existence is dependent on the simple and immaterial monads. Leibniz's cosmology, with its central monad, embraced a traditional Christian Theism and was more of a Personalism than the naturalistic Pantheism of Spinoza.
Bishop Berkeley, in seeking to find out what we could know with certainty, decided that our knowledge must be based on our perceptions. This led him to conclude that there was indeed no "real" knowable object behind one's perception, that what was "real" was the perception itself. This is characterised by Berkeley's slogan: "Esse est aut percipi aut percipere" or "To be is to be perceived or to perceive", meaning that something only exists, in the particular way that it is seen to exist, when it is being perceived (seen, felt, etc.) by an observing subject.
This subjective idealism or dogmatic idealism led to his placing the full weight of justification on our perceptions. This left Berkeley with the problem of explaining how it is that each of us apparently has much the same sort of perceptions of an object. He solved this problem by having God intercede, as the immediate cause of all of our perceptions.
Schopenhauer wrote: "Berkeley was, therefore, the first to treat the subjective starting-point really seriously and to demonstrate irrefutably its absolute necessity. He is the father of idealism...." (Parerga and Paralipomena, Vol. I, "Fragments for the History of Philosophy," § 12) Schopenhauer could have said, instead, that Berkeley was the "father" of the modern variety of idealism that is motivated, primarily, by epistemological considerations--as distinct from the more purely metaphysical idealism of (for example) Plotinus or Hegel. Bishop Berkeley therefore is considered the first modern philosopher known as an idealist. His immaterialism held that objects exist by the good quality of our perception of them. In other words, they are ideas residing in our awareness - as well as in the consciousness of the Divine Being.
Arthur Collier published the same assertions that were made by Berkeley. However, there seemed to have been no influence between the two contemporary writers. Collier claimed that the represented image of an external object is the only knowable reality. Matter, as a cause of the representative image, is unthinkable and therefore nothing to us. An external world, as absolute matter, unrelated to an observer, does not exist for human perceivers. As an appearance in a mind, the universe cannot exist as it appears if there is no perceiving mind.
Collier was influenced by John Norris's (1701) An Essay Towards the Theory of the Ideal or Intelligible World. The idealist statements by Collier were generally dismissed by readers who were not able to reflect on the distinction between a mental idea or image and the object that it represents.
Immanuel Kant held that the mind shapes the world as we perceive it to take the form of space-and-time. Kant focused on the idea drawn from British empiricism (and its philosophers such as Locke, Berkeley, and Hume) that all we can know is the mental impressions, or phenomena, that an outside world, which may or may not exist independently, creates in our minds; our minds can never perceive that outside world directly. Kant emphasized the difference between things as they appear to an observer and things in themselves, "..;that is, things considered without regard to whether and how they may be given to us ... ."Critique of Pure Reason, A 140
- I remove the thinking subject, the whole material world must at once vanish because it is nothing but a phenomenal appearance in the :sensibility of ourselves as a subject, and a manner or species of representation.Critique of Pure Reason A383}}
Kant's postscript to this added that the mind is not a blank slate, tabula rasa, (contra John Locke), but rather comes equipped with categories for organising our sense impressions. This Kantian sort of idealism opens up a world of abstractions (i.e., the universal categories minds use to understand phenomena) to be explored by reason, but in sharp contrast to Plato's, confirms uncertainties about a (un)knowable world outside our own minds. We cannot approach the noumenon, the "Thing in Itself" (German: Ding an Sich) outside our own mental world. (Kant's idealism goes by the counterintuitive name of transcendental idealism.)
Kant distinguished his transcendental or critical idealism from previous varieties:
- "The dictum of all genuine idealists, from the Eleatic school to Bishop Berkeley, is contained in this formula: “All knowledge through the senses and experience is nothing but sheer illusion, and only in the ideas of the pure understanding and reason is there truth.” The principle that throughout dominates and determines my idealism is, on the contrary: “All knowledge of things merely from pure understanding or pure reason is nothing but sheer illusion, and only in experience is there truth.”Prolegomena
Johann Fichte denied Kant's noumenon, and made the claim that consciousness made its own foundation, that the mental ego of the self relied on no external, and that an external of any kind would be the same as admitting a real material. He was the first to make the attempt at a pre-suppositionless theory of knowledge, wherein nothing outside of thinking would be assumed to exist outside the initial analysis of concept. So that conception could be solely grounded in itself, and assume nothing without deduction from there first, what he called a Wissenschaftslehre. (This stand is very similar to Giovanni Gentile's Actual Idealism, except that Gentile's theory goes further by denying a ground for even an ego or self made from thinking.)
Hegel, another philosopher whose system has been called idealism, argued in his Science of Logic (1812-1814) that finite qualities are not fully "real," because they depend on other finite qualities to determine them. Qualitative infinity, on the other hand, would be more self-determining, and hence would have a better claim to be called fully real. Similarly, finite natural things are less "real"--because they're less self-determining--than spiritual things like morally responsible people, ethical communities, and God. So any doctrine, such as materialism, that asserts that finite qualities or merely natural objects are fully real, is mistaken. Hegel called his philosophy absolute idealism, in contrast to the "subjective idealism" of Berkeley and the "transcendental idealism" of Kant and Fichte, which were not based (like Hegel's idealism) on a critique of the finite. The "idealists" listed above whose philosophy Hegel's philosophy most closely resembles are Plato and Plotinus. None of these three thinkers associates their idealism with the epistemological thesis that what we know are "ideas" in our minds. (An account of Hegel's critique of the finite, and of the "absolute idealism" that Hegel bases on that critique, can be found in Robert M. Wallace, Hegel's Philosophy of Reality, Freedom, and God (Cambridge: Cambridge University Press, 2005).
It is a noteworthy fact that many commentators on Hegel, and even some who admire Hegel's philosophy, fail to distinguish his type of idealism from Berkeley's and Kant's. Hegel certainly intends to preserve what he takes to be true in Kant's idealism, in particular Kant's insistence that ethical reason can and does go beyond finite "inclinations". But Hegel doesn't endorse Kant's conception of the "thing-in-itself," or the type of epistemological argument that led Kant to that conception. Still less does Hegel endorse Berkeley's notion that things exist only by being perceivers or being perceived. The guiding idea behind Hegel's "absolute idealism" is the observation, which he shares with Plato, that the exercise of reason enables the reasoner to achieve a kind of reality (namely, self-determination, or reality as oneself) that mere physical objects like rocks can't achieve. By giving this observation a central role in his thinking, Hegel contributes to a philosophical tradition, beginning with Plato, that has been obscured by the modern preoccupation with the epistemological problem of the subject's access to the "external world."
In the first volume of his Parerga and Paralipomena, Schopenhauer wrote his "Sketch of a History of the Doctrine of the Ideal and the Real". He defined the ideal as being mental pictures that constitute subjective knowledge. The ideal, for him, is what can be attributed to our own minds. The images in our head are what comprise the ideal. Schopenhauer emphasized that we are restricted to our own consciousness. The world that appears is only a representation or mental picture of objects. We directly and immediately know only representations. All objects that are external to the mind are known indirectly through the mediation of our mind.
Schopenhauer's history is an account of the concept of the "ideal" in its meaning as "ideas in a subject's mind." In this sense, "ideal" means "ideational" or "existing in the mind as an image." He does not refer to the other meaning of "ideal" as being qualities of the highest perfection and excellence. In his On the Freedom of the Will, Schopenhauer noted the ambiguity of the word "idealism" by calling it a "term with multiple meanings."
- True philosophy must at all costs be idealistic; indeed, it must be so merely to be honest. For nothing is more certain than that no one ever came :out of himself in order to identify himself immediately with things different from him; but everything of which he has certain, sure, and therefore :immediate knowledge, lies within his consciousness. Beyond this consciousness, therefore, there can be no immediate certainty ... .
- There can never be an existence that is objective absolutely and in itself; such an existence, indeed, is positively inconceivable. For the objective, :as such, always and essentially has its existence in the consciousness of a subject; it is therefore the subject's representation, and consequently is :conditioned by the subject, and moreover by the subject's forms of representation, which belong to the subject and not to the object.|The World :as Will and Representation, Vol. II, Ch. 1
It is evident that Schopenhauer's "idealism" is based primarily on considerations having to do with the relation between our ideas and external reality, rather than being based (like Plato's, Plotinus's, or Hegel's "idealism") on considerations having to do with the nature of reality as such.
British idealism enjoyed ascendancy in English-speaking philosophy in the later part of the 19th century. F. H. Bradley of Merton College, Oxford, saw reality as a monistic whole, which is apprehended through "feeling", a state in which there is no distinction between the perception and the thing perceived. Like Berkeley, Bradley thought that nothing can be known to exist unless it is known by a mind. Template:Quotation
Bradley was the apparent target of G. E. Moore's radical rejection of idealism. Moore claimed that Bradley did not understand the statement that something is real. We know for certain, through common sense and prephilosophical beliefs, that some things are real, whether they are objects of thought or not, according to Moore. In this way, he disagreed with Bradley's assertion that we cannot think of anything that really exists unless we have a thought of it in our mind.
J. M. E. McTaggart of Cambridge University, argued that minds alone exist, and that they only relate to each other through love. Space, time and material objects are for McTaggart unreal. He argued, for instance, in The Unreality of Time that it was not possible to produce a coherent account of a sequence of events in time, and that therefore time is an illusion. His book The Nature of Experience (1927) contained his arguments that space, time, and matter cannot possibly be real. In his Studies in Hegelian Cosmology, Cambridge, 1901, p. 196, he declared that metaphysics are not relevant to social and political action. McTaggart "..;thought that Hegel was wrong in supposing that metaphysics could show that the state is more than a means to the good of the individuals who compose it."(The Encyclopedia of Philosophy, vol. 3, "Idealism," New York, 1967) For McTaggart, "...philosophy can give us very little, if any guidance in action... . Why should a Hegelian citizen be surprised that his belief as to the organic nature of the Absolute does not help him in deciding how to vote? Would a Hegelian engineer be reasonable in expecting that his belief that all matter is spirit should help him in planning a bridge?
In The Grammar of Science, Preface to the 2nd Edition, 1900, Karl Pearson wrote, "There are many signs that a sound idealism is surely replacing, as a basis for natural philosophy, the crude materialism of the older physicists." This book influenced Einstein's regard for the importance of the observer in scientific measurements. In § 5 of that book, Pearson asserted that "...science is in reality a classification and analysis of the contents of the mind...." Also, "...the field of science is much more consciousness than an external world."
Criticism of Idealism
In the 1st edition (1781) of his Critique of Pure Reason, Kant described Idealism as such. Template:Quotation In the 2nd edition (1787) of his Critique of Pure Reason, he wrote a section called Refutation of Idealism to distinguish his transcendental idealism from Descartes's Sceptical Idealism and Berkeley's Dogmatic Idealism. In addition to this refutation in both the 1781 & 1787 editions the section "Paralogisms of Pure Reason" is an implicit critique of Descartes' Problematic Idealism, namely the Cogito. He says that just from "the spontaneity of thought" (cf. Descartes' Cogito) it is not possible to infer the 'I' as an object. In his Notes and Fragments ( 6315,1790-91; 18:618) Kant defines idealism in the following manner:
" The assertion that we can never be certain whether all of our putative outer experience is not mere imagining is idealism "
Søren Kierkegaard's primary criticism against Hegel is based around Hegel's claim to have developed a fully comprehensive system that could explain the whole of reality. The quote commonly used to express this idea, whether fair to Hegel or not, is, "What is rational is actual; and what is actual is rational," in the Elements of the Philosophy of Right (1821). Kierkegaard asserts that reality can be a system for God, but it cannot be so for any human individual, because both reality and humans are incomplete, and all philosophical systems imply completeness. Kierkegaard attacked Hegel's idealist philosophy in several of his works, but most succinctly in Concluding Unscientific Postscript (1846).
In the Postscript, Kierkegaard, as the pseudonymous philosopher Johannes Climacus, argues that a logical system is possible but an existential system is impossible. Hegel argues that once one has reached an ultimate understanding of the logical structure of the world, one has also reached an understanding of the logical structure of God's mind. Climacus claims Hegel's absolute idealism mistakenly blurs the distinction between existence and thought. Climacus also argues that our mortal nature places limits on our understanding of reality. As Climacus argues: "So-called systems have often been characterized and challenged in the assertion that they abrogate the distinction between good and evil, and destroy freedom. Perhaps one would express oneself quite as definitely, if one said that every such system fantastically dissipates the concept existence. ... Being an individual man is a thing that has been abolished, and every speculative philosopher confuses himself with humanity at large; whereby he becomes something infinitely great, and at the same time nothing at all."
A major concern of Hegel's Phenomenology of Spirit (1807) and of the philosophy of Spirit that he lays out in his Encyclopedia of the Philosophical Sciences (1817-1830) is the interrelation between individual humans, which he conceives in terms of "mutual recognition." However, what Climacus means by the aforementioned statement, is that Hegel, in the Philosophy of Right, believed the best solution was to surrender one's individuality to the customs of the State, identifying right and wrong in view of the prevailing bourgeois morality. Individual human will ought, at the State's highest level of development, to properly coincide with the will of the State. Climacus rejects Hegel's suppression of individuality by pointing out it is impossible to create a valid set of rules or system in any society which can adequately describe existence for any one individual. Submitting one's will to the State denies personal freedom, choice, and responsibility.
In addition, Hegel does believe we can know the structure of God's mind, or ultimate reality. Hegel agrees with Kierkegaard that both reality and humans are incomplete, inasmuch as we are in time, and reality develops through time. But the relation between time and eternity is outside time and this is the "logical structure" that Hegel thinks we can know. Kierkegaard disputes this assertion, because it eliminates the clear distinction between ontology and epistemology. Existence and thought are not identical and one cannot possibly think existence. Thought is always a form of abstraction, and thus not only is pure existence impossible to think, but all forms in existence are unthinkable; thought depends on language, which merely abstracts from experience, thus separating us from lived experience and the living essence of all beings. In addition, because we are finite beings, we cannot possibly know or understand anything that is universal or infinite such as God, so we cannot know God exists, since that which transcends time simultaneously transcends human understanding.
Friedrich Nietzsche was the first to mount a logically serious criticism of Idealism that has been popularised by David Stove (see below). He pre-empts Stove's GEM by arguing that Kant's argument for his transcendental idealism rests on a confusion between a tautology and begging the question, and therefore is an invalid, improper argument.
In his book Beyond Good and Evil, Part 1 On the Prejudice of Philosophers Section 11, he ridicules Kant for admiring himself because he had undertaken and (thought he) succeeded in tackling "the most difficult thing that could ever be undertaken on behalf of metaphysics."
Quoting Nietzsche's prose:
- "But let us reflect; it is high time to do so. 'How are synthetic judgements a priori possible?' Kant asked himself-and what really is his answer? 'By virtue of a faculty' - but unfortunately not in five words,...The honeymoon of German philosophy arrived. All the young theologians of the Tübingen seminary went into the bushes all looking for 'faculties.'...'By virtue of a faculty' - he had said, or at least meant. But is that an answer? An explanation? Or is it not rather merely a repetition of the question? How does opium induce sleep? 'By virtue of a faculty,' namely the virtus dormitiva, replies the doctor in Moliére."
- There are still harmless self-observers who believe that there are "immediate certainties"; for example, "I think," or as the superstition of Schopenhauer put it, "I will"; as though knowledge here got hold of its objects purely and nakedly as "the thing in itself," without any falsification on the part of either the subject or the object. But that "immediate certainty," as well as "absolute knowledge" and the "thing in itself," involved a contradictio in adjecto, (contradiction between the noun and the adjective) I shall repeat a hundred times; we really ought to free ourselves from the seduction of words!
G. E. Moore
The first criticism of Idealism that falls within the analytic philosophical framework is by one of its co-founders Moore. This 1903 seminal article, The Refutation of Idealism. This one of the first demonstrations of Moore's commitment to analysis as the proper philosophical method.
Moore proceeds by examining the Berkeleian aphorism esse est percipi: "to be is to be perceived". He examines in detail each of the three terms in the aphorism, finding that it must mean that the object and the subject are necessarily connected. So, he argues, for the idealist, "yellow" and "the sensation of yellow" are necessarily identical - to be yellow is necessarily to be experienced as yellow. But, in a move similar to the open question argument, it also seems clear that there is a difference between "yellow" and "the sensation of yellow". For Moore, the idealist is in error because "that esse is held to be percipi, solely because what is experienced is held to be identical with the experience of it".
Though far from a complete refutation. This was the first strong statement by analytic philosophy against its idealist predecessors--or at any rate against the type of idealism represented by Berkeley--this argument did not show that the GEM (in post Stove vernacular, see below) is logically invalid. Arguments advanced by Nietzsche (prior to Moore), Russell (just after Moore) & 80 years later Stove put a nail in the coffin for the "master" argument supporting (Berkeleyan) idealism.
Despite Bertrand Russell's hugely popular book The Problems of Philosophy (this book was in its 17th printing by 1943) which was written for a general audience rather than academia, few ever mention his critique even though he completely anticipates David Stove's GEM both in form and content (see below for David Stove's GEM). In chapter 4 (Idealism) he highlights Berkeley's tautological premise for advancing idealism.
Quoting Russell's prose (1912:42-43):
- "If we say that the things known must be in the mind, we are either un-duly limiting the mind's power of knowing, or we are uttering a mere tautology. We are uttering a mere tautology if we mean by 'in the mind' the same as by 'before the mind', i.e. if we mean merely being apprehended by the mind. But if we mean this, we shall have to admit that what, in this sense, is in the mind, may nevertheless be not mental. Thus when we realize the nature of knowledge, Berkeley's argument is seen to be wrong in substance as well as in form, and his grounds for supposing that 'idea'-i.e. the objects apprehended-must be mental, are found to have no validity whatever. Hence his grounds in favour of the idealism may be dismissed."
Published in 1933, A. C. Ewing, according to David Stove, mounted the first full length book critique of Idealism, entitled Idealism; a critical survey. Stove does not mention that Ewing anticipated his GEM.
The Australian philosopher David Stove argued in typical acerbic style that idealism rested on what he called "the worst argument in the world". From a logical point of view his critique is no different from Russell or Nietzsche's -- but Stove has been more widely cited and most clearly highlighted the mistake of proponents (like Berkeley) of subjective idealism. He named the form of this argument - invented by Berkeley -- "the GEM". Berkeley claimed that "[the mind] is deluded to think it can and does conceive of bodies existing unthought of, or without the mind, though at the same time they are apprehended by, or exist in, itself". Stove argued that this claim proceeds from the tautology that nothing can be thought of without its being thought of, to the conclusion that nothing can exist without its being thought of.
In The Construction of Social Reality John Searle offers an attack on some versions of idealism. Searle conveniently summarises two important arguments for (subjective) idealism. The first is based on our perception of reality:
- 1. All we have access to in perception are the contents of our own experiences
- 2. The only epistemic basis we can have for claims about the external world are our perceptual experiences
- 3. the only reality we can meaningfully speak of is the reality of perceptual experiences (The Construction of Social Reality p. 172)
Whilst agreeing with (2), Searle argues that (1) is false, and points out that (3) does not follow from (1) and (2).
The second argument for (subjective) idealism runs as follows:
- Premise: Any cognitive state occurs as part of a set of cognitive states and within a cognitive system
- Conclusion 1: It is impossible to get outside of all cognitive states and systems to survey the relationships between them and the reality they are used to cognize
- Conclusion 2: No cognition is ever of a reality that exists independently of cognition (The Construction of Social Reality p. 174)
Searle goes on to point out that conclusion 2 simply does not follow from its precedents.
Alan Musgrave in an article titled Realism and Antirealism in R. Klee (ed), Scientific Inquiry: Readings in the Philosophy of Science, Oxford, 1998, 344-352 - later re-titled to Conceptual Idealism and Stove's GEM in A. Musgrave, Essays on Realism and Rationalism, Rodopi, 1999 also in M.L. Dalla Chiara et al. (eds), Language, Quantum, Music, Kluwer, 1999, 25-35 - Alan Musgrave argues in addition to Stove's GEM, Conceptual Idealists compound their mistakes with use/mention confusions and proliferation of unnecessary hyphenated entities.
stock examples of use/mention confusions:
- Santa Claus (the person) does not exist.
- 'Santa Claus' (the name/concept/fairy tale) does exist; because adults tell children this every Christmas season.
The distinction in philosophical circles is highlighted by putting quotations around the word when we want to refer only to the name and not the object.
stock examples of hyphenated entities:
- things-in-itself (Immanuel Kant)
- things-as-interacted-by-us (Arthur Fine)
- Table-of-commonsense (Sir Arthur Eddington)
- Table-of-physics (Sir Arthur Eddington)
Hyphenated entities are "warning signs" for conceptual idealism according to Musgrave because they over emphasise the epistemic (ways in which people come to learn about the world) activities and will more likely commit errors in use/mention. These entities do not exist (strictly speaking and are ersatz entities) but highlight the numerous ways in which people come to know the world.
In Sir Arthur Eddington's case use/mention confusions compounded his problem when he thought he was sitting at two different tables in his study (table-of-commonsense and table-of-physics). In fact Eddington was sitting at one table but had two different perspectives or ways of knowing about that one table.
Richard Rorty and Postmodernist Philosophy in general have been attacked by Musgrave for committing use/mention confusions. Musgrave argues that these confusions help proliferate GEM's in our thinking and serious thought should avoid GEM's.
Philip J. Neujahr
"Although it would be hard to legislate about such matters, it would perhaps be well to restrict the idealist label to theories which hold that the world, or its material aspects, are dependent upon the specifically cognitive activities of the mind or Mind in perceiving or thinking about (or 'experiencing') the object of its awareness." (Kant's Idealism, Ch. 1)
Idealism in religious thought
A broad enough definition of idealism could include most religious viewpoints. The belief that personal beings (e.g., God and the angels) preceded the existence of insentient matter seems to suggest that an experiencing subject is a necessary reality. Also, the existence of an omniscient God suggests, regardless of the actual nature of matter, that all of nature is the object of at least one consciousness. Materialism sees no incoherence in a scenario of there being a cosmos where no sentient subject ever develops; a wholly unknown universe where neither any subject, nor any object of a subject's experience ever exists. Historically, Mechanistic Materialism has been the favorite viewpoint of Atheist philosophers. Still, idealistic viewpoints that have not included God, supernatural beings, or a post-mortem existence have sometimes been advanced.
While many religious philosophies are indeed specifically idealist, for example, some Hindu denominations view regarding the nature of Brahman, souls, and the world are idealistic, some have favored a form of substance dualism. Mahayana Buddhist denominations have usually embraced some form of idealism, while some Christian theologians have held idealist views, substance dualism has been the more common view of Christian authors, especially with the strong influence of the philosophy of Aristotle among the Scholastics.
The theology of Christian Science includes a form of subjective idealism: it teaches that all that exists is God and God's ideas; that the world as it appears to the senses is a distortion of the underlying spiritual reality.
A Course in Miracles, a spiritual self-study course published in 1976, represents an explicitly idealist, pure nondualistic thought system. In the Course, only God and His Creation, which is Spirit and has nothing to do with the world, are real. The physical universe is an illusion and does not exist. The Course compares the world of perception with a dream. It arises from the projection of the dreamer, i.e. the mind ("projection makes perception," T-21.in.1:5), according to its wishes (perception "is the outward picture of a wish; an image that you wanted to be true," T-24.VII.8:10). The purpose of the perceptual world is to ensure our separate, individual existence apart from God but avoid the responsibility and project the guilt onto others. As we learn to give the world another purpose and recognize our perceptual errors, we also learn to look past them or "forgive," as a way to awaken gradually from the dream and finally remember our true Identity in God. The Course’s nondualistic metaphysics is similar to Advaita Vedanta. However, A Course in Miracles differs in that it adds a "motivation" for the illusory existence of the perceptual world (for a further discussion, see Wapnick, Kenneth: The Message of A Course in Miracles, 1997, ISBN 0-933291-25-6).
In general parlance, "idealism" or "idealist" is also used to describe a person having high ideals, sometimes with the connotation that those ideals are unrealisable or at odds with "practical" life.
The word "ideal" is commonly used as an adjective to designate qualities of perfection, desirability, and excellence. This is foreign to the epistemological use of the word "idealism" which pertains to internal mental representations. These internal ideas represent objects that are assumed to exist outside of the mind.
- See especially Plato, Parmenides 132b3-c8.
- Bernard Williams, "Philosophy," in M.I. Finley, ed., The Legacy of Greece: A New Appraisal (Oxford: Clarendon Press, 1981), pp. 204-5; and Myles Burnyeat, "Idealism and Greek Philosophy: What Descartes Saw and Berkeley Missed," Philosophical Review 91 (1982), pp. 3-40.
- Paul Natorp, Plato's Theory of Ideas. An Introduction to Idealism, edited with an introduction by Vasilis Politis, translated by Vasilis Politis and John Connolly (Sankt Augustin: Akademia, 2005).
- See Vasilis Politis, "Non-Subjective Idealism in Plato (Sophist 248e-249d)," and John Dillon, "The Platonic Forms as Gesetze: Could Paul Natorp Have Been Right?", both in Stephen Gersh and Dermot Moran, eds., Eriugena, Berkeley, and the Idealist Tradition (Notre Dame, Indiana: University of Notre Dame Press, 2006).
- Ludwig Noiré, Historical Introduction to Kant's Critique of Pure Reason
- Critique of Pure Reason, A 140
- An account of Hegel's critique of the finite, and of the "absolute idealism" that Hegel bases on that critique, can be found in Robert M. Wallace, Hegel's Philosophy of Reality, Freedom, and God (Cambridge: Cambridge University Press, 2005).
- A book that is devoted to showing that Hegel is neither a Berkeleyan nor a Kantian idealist is Kenneth Westphal, Hegel's Epistemological Realism (Dordrecht: Kluwer, 1989).
- See Wallace, Hegel's Philosophy of Reality, Freedom, and God, chapter 3, for details on how Hegel intends to preserve something resembling Kant's dualism of nature and freedom while defending it against skeptical attack.
- The Encyclopedia of Philosophy, vol. 3, "Idealism," New York, 1967
- Studies in Hegelian Cosmology, ibid.
- Immanuel Kant's Critique of Pure Reason with an historical introduction by Ludwig Noiré, available at 
- Neujahr, Philip J., Kant's Idealism, Mercer University Press, 1995 ISBN 0-86554-476-X
- Kierkegaard, Søren. Concluding Unscientific Postscript, Princeton, ISBN 978-0-691-02081-5
- Watts, Michael. Kierkegaard, Oneworld, ISBN 978-1-85168-317-8
- A.C. Grayling-Wittgenstein on Scepticism and Certainty
- Science and Health with Key to the Scriptures by Mary Baker Eddy: idealism in religious thought
- 'The Triumph of Idealism', lecture by Professor Keith Ward offering a positive view of Idealism, at Gresham College, 13 March 2008 (available in text, audio, and video download)