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Short description: Philosophical view

Idealism in philosophy, also known as philosophical idealism or metaphysical idealism, is the set of metaphysical perspectives asserting that, most fundamentally, reality is equivalent to mind, spirit, or consciousness; that reality is entirely a mental construct; or that ideas are the highest form of reality or have the greatest claim to being considered "real".[1][2] The latter view is often first credited to the Ancient Greek philosopher Plato as part of a theory now known as Platonic idealism. The term "transcendental idealism" may also be applied to the related idea in epistemology which states that our knowledge of reality (things in themselves) is completely based on mental structures. This view was famously defended by Kant.[2]

There are numerous forms of idealism, which makes it difficult to define the term.[2] Indian philosophy contains some of the first defenses of idealism, such as in Vedanta and in Shaiva Pratyabhijña thought. These systems of thought argue for an all-pervading consciousness as the true nature and ground of reality.[3] Idealism is also found in some streams of Mahayana Buddhism, such as in the Yogācāra school, which argued for a "mind-only" (cittamatra) philosophy on an analysis of subjective experience.[4]

Epistemologically, idealism is accompanied by a rejection of the possibility of knowing the existence of any thing independent of mind. Ontologically, idealism asserts that the existence of all things depends upon mind;[5] thus, ontological idealism rejects the perspectives of physicalism and dualism. In contrast to materialism, idealism asserts the primacy of consciousness as the origin and prerequisite of all phenomena.

In Western philosophy, idealism was famously defended by George Berkeley and was a dominant metaphysical view in the 19th century.[2] Other types of western idealism include various forms of German idealism, such as that of Leibniz, Hegel, Fichte, Schelling and Schopenhauer, and different systems of British idealism like those of F. H. Bradley, J. M. E. McTaggart and Timothy Sprigge.

Idealism came under heavy attack in the West at the turn of the 20th century. The most influential critics were G. E. Moore and Bertrand Russell,[6] but its critics also included the new realists and Marxists. The attacks by Moore and Russell were so influential that even more than 100 years later "any acknowledgment of idealistic tendencies is viewed in the English-speaking world with reservation." However, many aspects and paradigms of idealism did still have a large influence on subsequent philosophy.[7]


Idealism is a term with several related meanings. It comes via Latin idea from the Ancient Greek idea (ἰδέα) from idein (ἰδεῖν), meaning "to see". The term entered the English language by 1743.[8][9] The term idealism was first used in the abstract metaphysical sense of the "belief that reality is made up only of ideas" by Christian Wolff in 1747.[10] The term re-entered the English language in this abstract sense by 1796.[11]

In ordinary language, as when speaking of Woodrow Wilson's political idealism, it generally suggests the priority of ideals, principles, values, and goals over concrete realities. Idealists are understood to represent the world as it might or should be, unlike pragmatists, who focus on the world as it presently is. In the arts, similarly, idealism affirms imagination and attempts to realize a mental conception of beauty, a standard of perfection, juxtaposed to aesthetic naturalism and realism.[12][13] The term idealism is also sometimes used in a sociological sense, which emphasizes how human ideas—especially beliefs and values—shape society.[14]

Regarding philosophical idealism proper, A. C. Ewing gave an influential definition for philosophical idealism which states that idealism is:

the view that there can be no physical objects existing apart from some experience...provided that we regard thinking as part of experience and do not imply by “experience” passivity, and provided we include under experience not only human experience but the so-called “Absolute Experience” or the experience of a God such as Berkeley postulates.[15]

A more recent definition by Willem deVries sees idealism as "roughly, the genus comprises theories that attribute ontological priority to the mental, especially the conceptual or ideational, over the non-mental."[15] As such, idealism entails a rejection of materialism (or physicalism) as well as the rejection of the mind-independent existence of matter (and as such, also entails a rejection of dualism).[16]

There are two main definitions of idealism in contemporary philosophy, depending on whether its thesis is epistemic or metaphysical:

  • Metaphysical idealism or ontological idealism is the view which holds that all of reality is in some way mental (or spirit, reason, or will) or at least ultimately grounded in a fundamental basis which is mental.[17] This is a form of metaphysical monism because it holds that there is only one type of thing in the universe. The modern paradigm of a Western metaphysical idealism is Berkeley's immaterialism.[17] Other such idealists are Hegel, and Bradley.
  • Epistemological idealism (or "formal" idealism) is a position in epistemology that holds that all knowledge is based on mental structures, not on "things in themselves". Whether a mind-independent reality is accepted or not, all that we have knowledge of are mental phenomena.[17] The main source of Western epistemic idealist arguments is the transcendental idealism of Kant.[17] Other thinkers who have defended epistemic idealist arguments include Ludwig Boltzmann and Brand Blanshard.

Thus, metaphysical idealism holds that reality itself is non-physical, immaterial or experiential at its core, while epistemological idealist arguments merely affirm that reality can only be known through ideas and mental structures (without necessarily making metaphysical claims about things in themselves).[18][19][20] Because of this, A.C. Ewing argued that instead of thinking about these two categories as forms of idealism proper, we should instead speak of epistemic and metaphysical arguments for idealism.[21]

These two ways of arguing for idealism are sometimes combined together to defend a specific type of idealism (as done by Berkeley), but they may also be defended as independent theses by different thinkers. For example, while F. H. Bradley and McTaggart focused on metaphysical arguments, Josiah Royce and Brand Blanshard developed epistemological arguments.[22]

Furthermore, one might use epistemic arguments, but remain neutral about the metaphysical nature of things in themselves. This metaphysically neutral position, which is not a form of metaphysical idealism proper, may be associated with figures like Rudolf Carnap, Quine, Donald Davidson and perhaps even Kant himself (though he is difficult to categorize).[23] The most famous kind of epistemic idealism is associated with Kantianism and transcendental idealism, as well as with the related Neo-Kantian philosophies. Transcendental idealists like Kant affirm epistemic idealistic arguments without committing themselves to whether reality as such, the "thing in itself," is ultimately mental. Thus, even though they may use the label "transcendental idealism", they are not metaphysical or ontological idealists like Hegel who affirm an absolute reality which is described as mental.[24]

Types of metaphysical idealism

Within metaphysical idealism, there numerous further sub-types, including forms of pluralism, which hold that there are many independent mental substances or minds, such as Leibniz' monadology, and various forms of monism or absolute idealism (e.g. Hegelianism or Advaita Vedanta), which hold that the fundamental mental reality is a single unity or is grounded some kind of singular Absolute. Beyond this, idealists disagree on which aspects of the mental are more metaphysically basic. Platonic idealism affirms that abstractions or ideal forms are more basic to reality than the things we perceive, while subjective idealists and phenomenalists tend to privilege sensory experiences over abstracta. Personalism meanwhile, sees persons or selves as fundamental.

A common distinction is between subjective and objective forms of idealism. Subjective idealists like George Berkeley reject the existence of a mind-independent or "external" world (though not the appearance of such phenomena in the mind). However, not all idealists restrict the real to subjective experience. Objective idealists make claims about a trans-empirical world, but simply deny that this world is essentially divorced from or ontologically prior mind or consciousness as such. Thus, objective idealism asserts that the reality of experiencing includes and transcends the realities of the object experienced and of the mind of the observer.[25]

Guyer et al. also distinguish between forms of idealism which are grounded in substance theory (often found in the Anglophone idealisms of the late nineteenth and twentieth centuries) and forms of idealism which focus on activities or dynamic processes (favored in post-Kantian German philosophy).[26]

Idealism is sometimes categorized as a type of metaphysical anti-realism or skepticism. However, many idealists do not reject the existence of an objective reality, they just argue that its nature is mental and that ideas are real.[27]

Classical Greek idealism

Pre-Socratic philosophy

There some precursors of idealism in Ancient Greek Philosophy, though scholars disagree on whether any of these thinkers could be properly labeled "idealist" in the modern sense.[28] One example is Anaxagoras (480 BC) who taught that all things in the universe (apeiron) were set in motion by Nous ("Mind"). In the Phaedo, Plato quotes him as sating: “it is intelligence [nous] that arranges and causes all things”.[28] Similarly, Parmenides famously stated that “thinking and being are the same”.[28] This has led some scholars, such as Hegel and E. D. Phillips, to label Parmenides as an idealist.[29]

Platonism and neoplatonism

Detail of Plato in The School of Athens, by Raphael

Plato's theory of forms or "ideas" (eidos) as described in dialogues like Phaedo, Parmenides and Sophist, describes ideal forms (for example the platonic solids in geometry or abstracts like Goodness and Justice), as perfect beings which “exists-by-itself ” (Greek: auto kath’ auto), i.e. independently of any particular instance (whether physical or in the individual thought of any person).[30][31] Anything which exists in the world exists by participating in one of these unique ideas, which are nevertheless interrelated causally with the world of becoming, with nature.[32] Arne Grøn calls this doctrine "the classic example of a metaphysical idealism as a transcendent idealism".[33] Nevertheless, Plato holds that matter as perceived by us is real, though transitory, imperfect, and dependent on the eternal ideas for its existence. Because of this, some scholars have seen Plato as a dualist, though others disagree and favor a monist account.[34][32]

The thought of Plato was widely influential, and later Late Platonist (or Neoplatonist) thinkers developed Platonism in new directions. Plotinus, the most influential of the Late Platonists, wrote “Being and Intellect are therefore one nature” (Enneads V.9.8).[35] According to scholars like Nathaniel Alfred Boll and Ludwig Noiré, with Plotinus, a true idealism which holds that only soul or mind exists appears for the first time in Western philosophy.[36][37][38][39] Similarly, for Maria Luisa Gatti, Plotinus’ philosophy is a "contemplationist metaphysics’, in which contemplation, as creative, constitutes the reason for the being of everything".[35] For Neoplatonist thinkers, the first cause or prinicple is the Idea of the Good, i.e. The One, from which everything is derived a hierarchical procession (proodos) (Enn. VI.7.15).[40]


Some Christian theologians have held idealist views,[41] often based on neoplatonism, despite the influence of Aristotelian scholasticism from the 12th century onward. However, there is certainly a sense in which some scholastic philosophers retained the Platonic idealism that came via Augustine.[42] For example, the work of John Scottus Eriugena has been interpreted as an idealistic philosophy by Dermot Moran who writes that for Scottus "all spatiotemporal reality is understood as immaterial, mind dependent, and lacking in independent existence”.[43] Scottus thus wrote: “the intellection of all the being of all things”.[44]

Later western theistic idealism such as that of Hermann Lotze offers a theory of the "world ground" in which all things find their unity: it has been widely accepted by Protestant theologians.[45]

Several modern religious movements, for example the organizations within the New Thought Movement and the Unity Church, may be said to have a particularly idealist orientation. The theology of Christian Science includes a form of idealism: it teaches that all that truly 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 distortion that may be corrected (both conceptually and in terms of human experience) through a reorientation (spiritualization) of thought.[46]

Idealism was also defended in medieval Jewish philosophy. According to Samuel Lebens, early Hassidic rabbis like Yitzchak Luria (1534–72) defended a form of Kabbalistic idealism in which the world was God's dream or a fictional tale told by God.[47]

Idealism in Eastern philosophy

The sage Yajnavalkya (possibly 8th century BCE) is one of the earliest exponents of idealism, and is a major figure in the Brihadaranyaka Upanishad.

There are currents of idealism throughout Indian philosophy, ancient and modern. Hindu idealism often takes the form of monism or non-dualism, espousing the view that a unitary consciousness is the essence or meaning of the phenomenal reality and plurality.

Buddhist idealism on the other hand is more epistemic and is not a metaphysical monism, which Buddhists consider eternalistic and hence not the Middle Way between extremes espoused by the Buddha.

The oldest reference to Idealism in Vedic texts is in Purusha Sukta of the Rig Veda. This Sukta espouses panentheism by presenting cosmic being Purusha as both pervading all universe and yet being transcendent to it.[48] Absolute idealism can be seen in Chāndogya Upaniṣad, where things of the objective world like the five elements and the subjective world such as will, hope, memory etc. are seen to be emanations from the Self.[49]

Hindu philosophy

Idealist notions have been propounded by the Vedanta schools of thought, which use the Vedas, especially the Upanishads as their key texts. Idealism was opposed by dualists Samkhya, the atomists Vaisheshika, the logicians Nyaya, the linguists Mimamsa and the materialists Cārvāka. There are various sub schools of Vedanta, like Advaita Vedanta (non-dual), Vishishtadvaita and Bhedabheda Vedanta (difference and non-difference).

The schools of Vedanta all attempt to explain the nature and relationship of Brahman (universal soul or Self) and Atman (individual self), which they see as the central topic of the Vedas. One of the earliest attempts at this was Bādarāyaņa's Brahma Sutras, which is canonical for all Vedanta sub-schools. Advaita Vedanta is a major sub school of Vedanta which holds a non-dual Idealistic metaphysics.

According to Advaita thinkers like Adi Shankara (788–820) and his contemporary Maṇḍana Miśra, Brahman, the single unitary consciousness or absolute awareness, appears as the diversity of the world because of maya or illusion, and hence perception of plurality is mithya, error. The world and all beings or souls in it have no separate existence from Brahman, universal consciousness, and the seemingly independent soul (jiva)[50] is identical to Brahman. These doctrines are represented in verses such as brahma satyam jagan mithya; jīvo brahmaiva na aparah (Brahman is alone True, and this world of plurality is an error; the individual self is not different from Brahman).

Other forms of Vedanta like the Vishishtadvaita of Ramanuja and the Bhedabheda of Bhāskara are not as radical in their non-dualism, accepting that there is a certain difference between individual souls and Brahman. Dvaita school of Vedanta by Madhvacharya maintains the opposing view that the world is real and eternal. It also argues that real Atman fully depends on the reflection of independent Brahman.

The Tantric tradition of Kashmir Shaivism has also been categorized by scholars as a form of Idealism.[51] The key thinkers of this tradition are the Kashmirian philosophers Utpaladeva (c. 900–950 CE) and Abhinavagupta (975–1025 CE).

Modern Hindu Idealism was defended by the influential Indian philosopher Sarvepalli Radhakrishnan in his 1932 An Idealist View of Life and other works, which espouse a modern form of Advaita Vedanta. The essence of Hindu Idealism is captured by such modern writers as Sri Nisargadatta Maharaj, Sri Aurobindo, P. R. Sarkar, and Sohail Inayatullah.

Buddhist philosophy

Statue of Vasubandhu (jp. Seshin), Kōfuku-ji, Nara, Japan

Buddhist views which can be said to be similar to Idealism appear in Mahayana Buddhist texts such as the Samdhinirmocana sutra, Laṅkāvatāra Sūtra, and Dashabhumika sutra.[52] These theories, known as "mind-only" (cittamatra) or "the consciousness doctrine" (vijñanavada) were later expanded upon by Indian Buddhist philosophers of the Yogacara school. These figures include: Vasubandhu, Asaṅga, Dignāga, Dharmakīrti, Sthiramati, Dharmapāla, Jñānaśrīmitra, Śaṅkaranandana, and Ratnākaraśānti.

Vasubandhu's works include a refutation of external mind-independent objects and argue that the true nature of reality is beyond subject-object distinctions.[53] He views ordinary conscious experience as deluded in its perceptions of an external world separate from itself (which does not exist), and instead argues that all there is vijñapti (ideas, mental images).[53][54] Hence, Vasubandhu begins his Twenty verses demonstrating consciousness-only by affirming that the whole world is consciousness-only and that external objects are non-existent, which he compares to seeing hairs due to an eye disease.[53] Likewise, the Buddhist philosopher Dharmakirti's view is summed up in the Pramānaṿārttika (Commentary on Epistemology) as follows: "cognition experiences itself, and nothing else whatsoever. Even the particular objects of perception, are by nature just consciousness itself."[55]

There is a modern scholarly disagreement about whether classic Indian Yogacara Buddhism can be said to be a form of idealism.[53] Some writers like philosopher Jay Garfield and German philologist Lambert Schmithausen argue that Vasubandhu and Indian Yogacarins are metaphysical idealists that reject the existence of a mind independent external world.[56] Others see him as closer to an epistemic idealist like Kant who holds that our knowledge of the world is simply knowledge of our own concepts and perceptions.[53] However, a major difference here is that while Kant holds that the thing-in-itself is unknowable, Indian Yogacarins held that ultimate reality is knowable, but only through the non-conceptual yogic perception of a highly trained meditative mind.[53]

Scholars like Dan Lusthaus and Thomas Kochumuttom who hold that Yogacara is not a metaphysical idealism argue that Yogācāra thinkers did not focus on consciousness to assert it as ontologically real or as the maker of the world, but simply to analyze the structure of experience in order to understand how suffering (dukkha) arises in the mind.[57][58]

Chinese philosophy

In Chinese philosophy, idealism was first defended by Chinese Yogacara Buddhists like Xuanzang (602-664) and his students Kuiji (632–682) and Wŏnch'ŭk (613–696). Xuanzang had studied Yogacara Buddhism at the great Indian university of Nalanda under the Indian philosopher Śīlabhadra. His work was pivotal in the establishment of East Asian Yogacara Buddhism, which also had an influence on the rest of East Asian Buddhist thought. Yogacara Buddhism also influenced the thought of other Chinese Buddhist philosophical traditions, such as that of the Huayan school.

Chinese Buddhist idealism also influenced Confucian philosophy through the work of thinkers like Wang Yangming. Wang was a Ming Chinese neo-Confucian who defended the view that objects do not exist entirely apart from the mind because the mind shapes them. It is not the world that shapes the mind but the mind that gives reason to the world, so the mind alone is the source of all reason, having an inner light, an innate moral goodness and understanding of what is good.

Yogacara philosophy saw a revival in the 20th century, associated figures like Yang Wenhui, Taixu, Liang Shuming, Ouyang Jingwu, and Lu Cheng. Both Buddhists and Confucian thinkers (like Xiong Shili) participated in this movement.[59]

Modern philosophy

It is only in the modern era that idealism became a central topic of argumentation among Western philosophers.[60] This was also when the term "idealism" coined by Christian Wolff (1679–1754), though previous thinkers like Berkeley had argued for it under different names.

Idealistic tendencies can be found in the work of some rationalist philosophers, like Leibniz and Nicolas Malebranche (though they did not use the term). Some scholars see Leibniz' philosophy as approaching idealism. Guyer et al. write that "his view that the states of monads can be only perceptions and appetitions (desires) suggests a metaphysical argument for idealism, while his famous thesis that each monad represents the entire universe from its own point of view might be taken to be an epistemological ground for idealism, even if he does not say as much."[60]

Subjective idealism

Main page: Philosophy:Subjective idealism

One famous proponent of modern idealism was Bishop George Berkeley (1685–1753), an Anglo-Irish philosopher who defended a theory he called immaterialism.[61] This kind of idealism is sometimes also called subjective idealism (also known as phenomenalistic idealism).

Berkeley held that objects exist only to the extent that a mind perceives them and thus the physical world does not exist outside of mind. Berkeley's epistemic argument for this view (found in his A Treatise Concerning the Principles of Human Knowledge) rests on the premise that we can only know ideas in the mind. Thus, knowledge does not extend to mind-independent things (Treatise, 1710: Part I, §2).[62] From this, Berkeley holds that “the existence of an idea consists in being perceived”, thus, regarding ideas "their esse is percipi," i.e. to be is to be perceived by mind (1710: Part I, §3).[62]

Based on this restriction of existence to only what is being perceived, Berkeley holds that it is meaningless to think that there could exist objects that are not being perceived.[62] This is the basic idea behind what has been called Berkeley's “master argument” for idealism, which states that "one cannot conceive of anything existing unconceived because in trying to do so one is still conceiving of the object" (1710: Part I, §23).[62] As to the question of how objects which are currently not being perceived by individual minds persist in the world, Berkeley answers that a single eternal mind keeps all of physical reality stable (and indeed, to cause ideas in the first place), and this is God.[63]

Berkeley also argued for idealism based on a second key premise: “an idea can be like nothing but an idea” and as such there cannot be any things without or outside mind. This is because for something to be like something else, there must be something they have in common. If something is mind independent, then it must be completely different from ideas. Thus, there can be no relation between ideas in the mind and things “without the mind,” since they are not alike.[64] As Berkeley writes, "...I ask whether those supposed originals or external things, of which our ideas are the pictures or representations, be themselves perceivable or no? if they are, then they are ideas, and we have gained our point; but if you say they are not, I appeal to any one whether it be sense, to assert a colour is like something which is invisible; hard or soft, like something which is intangible; and so of the rest." (1710: Part I, §8).[64]

A similar idealistic philosophy was developed at around the same time as Berkeley by Anglican priest and philosopher Arthur Collier (Clavis Universalis: Or, A New Inquiry after Truth, Being a Demonstration of the Non-Existence, or Impossibility, of an External World, 1713). Collier claimed to have developed his view that all matter depends on mind independently of Berkeley.[65] Paul Brunton, a British philosopher and mystic, also taught a similar type of idealism called "mentalism".[66]

A. A. Luce[67] and John Foster are other subjective idealists.[68] Luce, in Sense without Matter (1954), attempts to bring Berkeley up to date by modernizing his vocabulary and putting the issues he faced in modern terms, and treats the Biblical account of matter and the psychology of perception and nature. Foster's The Case for Idealism argues that the physical world is the logical creation of natural, non-logical constraints on human sense-experience. Foster's latest defense of his views (phenomenalistic idealism) is in his book A World for Us: The Case for Phenomenalistic Idealism.

Critics of subjective idealism include Bertrand Russell's popular 1912 book The Problems of Philosophy, Australian philosopher David Stove,[69] Alan Musgrave,[70] and John Searle.[71]

Epistemic & Transcendental

Main page: Philosophy:Transcendental idealism

Transcendental idealism is a doctrine founded by Immanuel Kant in the eighteenth century. It maintains that we cannot know more of reality that its appearance to us, that is, according to our capacities of sensibility and understanding. Since it focuses on the mind dependent nature of knowledge and not on metaphysics per se, Transcendental idealism is a type of epistemological idealism.

His Critique of Pure Reason (2nd ed.) contains a section entitled "Refutation of Idealism", which distinguishes transcendental idealism from Descartes's sceptical idealism and Berkeley's anti-realist strain of subjective idealism. The section "Paralogisms of Pure Reason" is also an implicit critique of Descartes's idealism. Kant says that it is not possible to infer the "I" as an object (Descartes' cogito ergo sum) purely from "the spontaneity of thought". Kant focused on ideas drawn from British philosophers such as Locke, Berkeley and Hume, but distinguished his transcendental or critical idealism from previous varieties:

The thesis of all genuine idealists, from the Eleatic School up to Bishop Berkeley, is contained in this formula: "All cognition through the senses and experience is nothing but sheer illusion, and there is truth only in the ideas of pure understanding and reason."
The principle that governs and determines my idealism throughout is, on the contrary: "All cognition of things out of mere pure understanding or pure reason is nothing but sheer illusion, and there is truth only in experience."[72]

Charles Bernard Renouvier was the first philosopher in France to formulate a complete idealistic system since Nicolas Malebranche. His system is based on Immanuel Kant's, as his chosen term "néo-criticisme" indicates. It is a transformation rather than a continuation of Kantianism.

The mid-19th century saw a revival of Kantian philosophy which became known as Neo-Kantianism (German: Neukantianismus). This movement was especially influential on 19th century German academic philosophy (and also continental philosophy as a whole). Some important figures include: Hermann Cohen, Ernst Cassirer, Hermann von Helmholtz, Eduard Zeller, Leonard Nelson, Heinrich Rickert, and Friedrich Albert Lange.[73]

The American philosopher Brand Blanshard was also a proponent of a type of epistemic idealism.

Schopenhauer's metaphysics

In the metaphysics of Arthur Schopenhauer, mental pictures or ideas are what 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. This is to say that we are restricted to our own consciousness. The world that appears is only ideas, images or "presentation" (German: vorstellung), which is all that we directly and immediately know. All objects that are external to the mind are known indirectly. In his own words, "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."[74]

Regarding the thing-in-itself, the ultimate ontological reality that underlies all ideas, Schopenhauer argues that it is a single unitary Will, beyond all categories (like space, time, and differentiation).

Objective idealism

Main page: Philosophy:Objective idealism

Objective idealism asserts that the reality of experiencing combines and transcends the realities of the object experienced and of the mind of the observer.[75] Proponents include Thomas Hill Green, Josiah Royce, Benedetto Croce, and Charles Sanders Peirce.

Absolute idealism

Main page: Philosophy:Absolute idealism

thumb|Hegel's The Phenomenology of Spirit was a pivotal work of German absolute idealism F. W. J. Schelling (1775–1854) claimed that J. G. Fichte's "I" needs the Not-I, because there is no subject without object, and vice versa. So there is no difference between the subjective and the objective, that is, the ideal and the real. This is Schelling's "absolute identity": the ideas or mental images in the mind are identical to the extended objects which are external to the mind.

Absolute idealism is G. W. F. Hegel's account of how existence is comprehensible as an all-inclusive whole. Hegel called his philosophy "absolute" idealism in contrast to the "subjective idealism" of Berkeley and the "transcendental idealism" of Kant and Fichte.[76] The exercise of reason and intellect enables the philosopher to know ultimate historical reality, the phenomenological constitution of self-determination, the dialectical development of self-awareness in the realm of history.

In his Science of Logic (1812–1814) Hegel argues 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 more fully real. Similarly finite natural things are less "real"—because they are 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 natural objects are fully real is mistaken.[77]

Hegel certainly intends to preserve what he takes to be true of German Idealism, in particular Kant's insistence that ethical reason can and does go beyond finite inclinations.[78] For Hegel there must be some identity of thought and being for the "subject" (any human observer) to be able to know any observed "object" (any external entity, possibly even another human) at all. Under Hegel's concept of "subject-object identity", subject and object both have spirit (Hegel's ersatz, redefined, nonsupernatural "God") as their inner reality—and in that sense are identical. But until spirit's "self-realization" occurs, the subject (a human mind) mistakenly thinks every "object" it observes is something "alien", meaning something separate or apart from "subject". In Hegel's words, "The object is revealed to it [to "subject"] by [as] something alien, and it does not recognize itself."[79] Self-realization occurs when the speculative philosopher (e.g., Hegel) arrives on the scene and realizes that every "object" is himself, because both subject and object are essentially spirit. When self-actualization is achieved and spirit knows itself absolutely, the "finite" human recognized itself as the "infinite" ("God", divine), replacing the supernatural God of "picture-thought" or "representation" [Vorstellung] characteristic of positive religion.[80]

Gentile's actual idealism

Actual idealism is a form of idealism developed by Giovanni Gentile which argues that reality is the ongoing act of thinking, or in Italian "pensiero pensante" and thus, only thoughts exist.[81][82] He further argued that our combined thoughts defined and produced reality.[82] Gentile also nationalizes this idea, holding that the state is a composition of many minds coming together to construct reality.[83] Giovanni Gentile was a key supporter of fascism, regarded by many as the "philosopher of fascism". His idealist theory argued for the unity of all society under one leader, which allows it to act as one body.[83]

Anglo-American Idealism

thumb|F.H. Bradley, a leading British absolute idealist

Idealism was widespread in Anglo-American philosophy during the nineteenth and twentieth centuries. It was the dominant metaphysics in the English speaking world during the last decades of the nineteenth century and the beginning of the twentieth century.[84] During this time, the defenders of British idealism made significant contributions to all fields of philosophy. Many Anglo-American idealists defended a type of Absolute idealism influenced by German idealism, especially the work of Hegel and other Neo-Hegelians. This was particularly popular in British idealism. However, other philosophers, like McTaggart, broke from this trend and instead defended a pluralistic idealism in which the ultimate reality is a plurality of minds.

Anglo-American forms of absolute idealism influenced by were very popular during the late nineteenth century. They were influenced by Hegelianism most of all, but also drew on Kant, Plato and Aristotle.[85] Key figures include many of the British idealists, such as T. H. Green (1836–1882), F. H. Bradley (1846–1924), Bernard Bosanquet (1848–1923), J. H. Muirhead (1855–1940), , H. H. Joachim (1868–1938), A. E. Taylor (1869–1945), R. G. Collingwood (1889–1943), G. R. G. Mure (1893–1979) and Michael Oakeshott.[86] American idealist philosophers include Josiah Royce (1855–1916) and Brand Blanshard (1892–1987).

A paradigmatic British absolute idealist is F.H. Bradley, who argues in Appearance and Reality that "the Absolute is not many; there are no independent reals" by critiquing the independence of relations.[87] This absolute reality is ultimately a experiential unity. Thus for Bradley, "the Absolute is one system, and ... its contents are nothing but sentient experience. It will hence be a single and all-inclusive experience, which embraces every partial diversity in concord."[88]

Pluralistic idealism

Pluralistic idealism takes the view that there are many individual minds that together underlie the existence of the observed world and make possible the existence of the physical universe.[89] Pluralistic idealism does not assume the existence of a single ultimate mental reality.

Idealistic theories of Personalism

Personalism is the view that the minds that underlie reality are the minds of persons. Borden Parker Bowne, a philosopher at Boston University, a founder and popularizer of personal idealism, presented it as a substantive reality of persons, the only reality, as known directly in self-consciousness. Reality is a society of interacting persons dependent on the Supreme Person of God. Other proponents include George Holmes Howison[90] and J. M. E. McTaggart.[91]

Howison's personal idealism [92] was also called "California Personalism" by others to distinguish it from the "Boston Personalism" which was of Bowne. Howison maintained that both impersonal, monistic idealism and materialism run contrary to the experience of moral freedom. To deny freedom to pursue truth, beauty, and "benignant love" is to undermine every profound human venture, including science, morality, and philosophy. Personalistic idealists Borden Parker Bowne and Edgar S. Brightman and realistic (in some senses of the term, though he remained influenced by neoplatonism) personal theist Saint Thomas Aquinas address a core issue, namely that of dependence upon an infinite personal God.[93]

Howison, in his book The Limits of Evolution and Other Essays Illustrating the Metaphysical Theory of Personal Idealism, created a democratic notion of personal idealism that extended all the way to God, who was no more the ultimate monarch but the ultimate democrat in eternal relation to other eternal persons. J. M. E. McTaggart's idealist atheism and Thomas Davidson's apeirotheism resemble Howisons personal idealism.[94]

J. M. E. McTaggart argued that minds alone exist and only relate to each other through love. Space, time and material objects are unreal. In The Unreality of Time he argued that time is an illusion because it is impossible to produce a coherent account of a sequence of events. The Nature of Existence (1927) contained his arguments that space, time, and matter cannot possibly be real. In his Studies in Hegelian Cosmology, he declared that metaphysics are not relevant to social and political action.[95] 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".[96] 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?"[97]

Thomas Davidson taught a philosophy called "apeirotheism", a "form of pluralistic idealism...coupled with a stern ethical rigorism"[98] which he defined as "a theory of Gods infinite in number". The theory was indebted to Aristotle's pluralism and his concepts of Soul, the rational, living aspect of a living substance which cannot exist apart from the body because it is not a substance but an essence, and nous, rational thought, reflection and understanding. Although a perennial source of controversy, Aristotle arguably views the latter as both eternal and immaterial in nature, as exemplified in his theology of unmoved movers.[99] Identifying Aristotle's God with rational thought, Davidson argued, contrary to Aristotle, that just as the soul cannot exist apart from the body, God cannot exist apart from the world.[100]

The English psychologist and philosopher James Ward inspired by Leibniz and panpsychism had also defended a form of pluralistic idealism.[101] According to Ward the universe is composed of "psychic monads" of different levels, interacting for mutual self-betterment.[102]

Modern critiques and contemporary idealisms

In the Western world, the popularity of idealism as a metaphysical view declined severely in 20th century, especially in English language analytic philosophy. This was partly due to the criticisms of British philosophers like G. E. Moore and Bertrand Russell.[103] Moore famously critiqued idealism and defended realism in A Defence of Common Sense and Proof of an External World. His most famous argument was an epistemological argument from common sense facts, sometimes known as "Here is one hand". Other modern critiques of idealism can be found in Bertrand Russell's popular 1912 book The Problems of Philosophy, and in the work of American "new realists" like E.B. Holt, Ralph Barton Perry and Roy Wood Sellars.[104]

For the most influential critics of idealism, Moore and Russell, idealist arguments falsely presuppose that the mind's relation to any object is a necessary condition for the existence of the object. As such, idealists often fail to distinguish “between act and object in our apprehending of things” (Russell).[104] Idealism is also critiqued in the works of Australian philosopher David Stove,[105] Alan Musgrave,[106] and John Searle.[107] Today, idealism remains a minority view in Western analytic circles.[104] In spite of this, the study of the work of the Anglo-American idealists saw a revival in the 21st century with an increase in publications at the turn of the century, and they are now considered to have made important contributions to philosophy.[108]

Several modern figures continue to defend idealism. Recent idealist philosophers include A. A. Luce (Sense without Matter, 1954), Timothy Sprigge (The Vindication of Absolute Idealism, 1984), Leslie Armour, Vittorio Hösle (Objective Idealism, 1998), John Andrew Foster (A World for Us, 2008),[109] John A. Leslie (Infinite Minds: A Philosophical Cosmology, 2002), and Bernardo Kastrup (The Idea of the World, 2018).

Idealistic theories based on 20th-century science

Idealist notions took a strong hold among physicists of the early 20th century confronted with the paradoxes of quantum physics and the theory of relativity. 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.[110] In § 5 of that book, Pearson asserted that " 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."

Arthur Eddington, a British astrophysicist of the early 20th century, wrote in his book The Nature of the Physical World that the stuff of the world is mind-stuff, adding that "The mind-stuff of the world is, of course, something more general than our individual conscious minds."[111] Ian Barbour, in his book Issues in Science and Religion, cites Arthur Eddington's The Nature of the Physical World (1928) as a text that argues The Heisenberg Uncertainty Principles provides a scientific basis for "the defense of the idea of human freedom" and his Science and the Unseen World (1929) for support of philosophical idealism "the thesis that reality is basically mental."[112]

The 20th-century British scientist Sir James Jeans wrote that "the Universe begins to look more like a great thought than like a great machine."

The physicist Sir James Jeans wrote: "The stream of knowledge is heading towards a non-mechanical reality; the Universe begins to look more like a great thought than like a great machine. Mind no longer appears to be an accidental intruder into the realm of matter... we ought rather hail it as the creator and governor of the realm of matter."[113] Jeans, in an interview published in The Observer (London), when asked the question: "Do you believe that life on this planet is the result of some sort of accident, or do you believe that it is a part of some great scheme?" replied, "I incline to the idealistic theory that consciousness is fundamental... In general the universe seems to me to be nearer to a great thought than to a great machine."

The chemist Ernest Lester Smith, a member of the occult movement theosophy, wrote a book Intelligence Came First (1975) in which he claimed that consciousness is a fact of nature and that the cosmos is grounded in and pervaded by mind and intelligence.[114]

Bernard d'Espagnat, a French theoretical physicist best known for his work on the nature of reality, wrote a paper titled The Quantum Theory and Reality. According to the paper, "The doctrine that the world is made up of objects whose existence is independent of human consciousness turns out to be in conflict with quantum mechanics and with facts established by experiment."[115]. In a The Guardian article entitled "Quantum Weirdness: What We Call 'Reality' is Just a State of Mind",[116] d'Espagnat wrote, "the basic components of objects – the particles, electrons, quarks etc. – cannot be thought of as 'self-existent'." He further writes that his research in quantum physics has led him to conclude that an "ultimate reality" exists, which is not embedded in space or time.[117]


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  56. Schmithausen, Lambert (2005). On the Problem of the External World in the Ch’eng wei shih lun. Tōkyō: The International Institute for Buddhist Studies. The International Institute for Buddhist Studies.
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  77. An interpretation of Hegel's critique of the finite, and of the "absolute idealism" which Hegel appears to base that critique, is found in Robert M. Wallace, Hegel's Philosophy of Reality, Freedom, and God, (Cambridge: Cambridge University Press, 2005).
  78. See Wallace, Hegel's Philosophy of Reality, Freedom, and God, chapter 3, for details on how Hegel might preserve something resembling Kant's dualism of nature and freedom while defending it against skeptical attack.
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  86. Connelly, James; Panagakou,Stamatoula. Anglo-American Idealism: Thinkers and Ideas, pp. 3-4. Peter Lang, 2010
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  89. "Metaphysical Idealism". 
  90. The Limits Of Evolution; And Other Essays Illustrating The Metaphysical Theory Of Personal Idealism By George Holmes Howison
  91. See the book Idealistic Argument in Recent British and American Philosophy By Gustavus W Cunningham page 202 "Ontologically I am an idealist, since i believe that all that exists is spiritual. I am also, in one sense of the term, a Personal Idealist."
  92. "George Holmes Howison". 
  93. Research & Articles on Howison, George Holmes (1834–1916) by. 2010-11-02. Retrieved 2012-08-17. 
  94. McLachlan, James (2006). "George Holmes Howison: 'The City of God' and Personal Idealism". The Journal of Speculative Philosophy 20 (3): 224–242. doi:10.1353/jsp.2007.0005. Project MUSE 209478. 
  95. (Cambridge, 1901, p.196)
  96. The Encyclopedia of Philosophy, vol. 3, "Idealism", New York, 1967
  97. Studies in Hegelian Cosmology ibid.
  98. Charles M. Bakewell, "Thomas Davidson", Dictionary of American Biography, gen. ed. Dumas Malone (New York: Charles Scribner's Sons, 1932), 96.
  99. Gerson, Lloyd P. (2004). "The Unity of Intellect in Aristotle's 'De Anima'". Phronesis 49 (4): 348–373. doi:10.1163/1568528043067005. "Desperately difficult texts inevitably elicit desperate hermeneutical measures. Aristotle's De Anima, book three, chapter five, is evidently one such text. At least since the time of Alexander of Aphrodisias, scholars have felt compelled to draw some remarkable conclusions regarding Aristotle's brief remarks in this passage regarding intellect. One such claim is that in chapter five, Aristotle introduces a second intellect, the so-called 'agent intellect', an intellect distinct from the 'passive intellect', the supposed focus of discussion up until this passage. This view is a direct descendant of the view of Alexander himself, who identified the agent intellect with the divine intellect. Even the staunchest defender of such a view is typically at a loss to give a plausible explanation of why the divine intellect pops into and then out of the picture in the intense and closely argued discussion of the human intellect that goes from chapter four through to the end of chapter seven.". 
  100. Davidson, Journal, 1884-1898 (Thomas Davidson Collection, Manuscript Group #169, Sterling Memorial Library, Yale University). Quoted in DeArmey, "Thomas Davidson's Apeirotheism", 692
  101. The New Cambridge Modern History: The era of violence, 1898-1945, edited by David Thomson University Press, 1960, p. 135
  102. Hugh Joseph Tallon The concept of self in British and American idealism 1939, p. 118
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  104. 104.0 104.1 104.2 Guyer, Paul; Horstmann, Rolf-Peter (30 August 2015). "Idealism". in Zalta, Edward N.. Stanford Encyclopedia of Philosophy. Stanford, California: Metaphysics Research Lab, Stanford University. 
  105. "Stove's discovery of the worst argument in the world". 
  106. 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
  107. John Searle, The Construction of Social Reality p. 174
  108. Connelly, James; Panagakou,Stamatoula. Anglo-American Idealism: Thinkers and Ideas, pp. 2, 6. Peter Lang, 2010
  109. Review for John Foster's book A World for Us: The Case for Phenomenalistic Idealism
  110. Whitworth, Michael H. (2002). Einstein's Wake: Relativity, Metaphor, & Modernist Literature. Oxford University Press. pp. 85–87. ISBN 0198186401. Retrieved 2019-07-27. 
  111. A.S. Eddington, The Nature of the Physical World, page 276-81.
  112. (1966), p. 133
  113. Sir James Jeans, The mysterious universe, page 137.
  114. Ernest Lester SmithIntelligence Came First Quest Books, 1990 ISBN:0-8356-0657-0
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  116. "Quantum weirdness: What We Call 'Reality' is Just a State of Mind" (20 March 2009).
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  • Foster, John Andrew. A World for Us: The Case for Phenomenalistic Idealism. Oxford University Press, Oxford, 2008. ISBN:0-19-929713-4
  • Dignāga; Krumroy, Robert E; Sastri, N. Aiyaswami. Ālambanaparīkṣā, and Vṛtti by Diṅnāga, with the Commentary of Dharmapāla, Restored Into Sanskrit from the Tibetan and Chinese Versions and Edited with English Translations and Notes and with Copious Extracts from Vinītadeva's Commentary. Jain Publishing Company, 2007.
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  • Dunham, Jeremy; Grant, Iain Hamilton; Watson, Sean. Idealism: The History of a Philosophy, Acumen, 2011, ISBN 9780773538375.
  • Goldschmidt, Tyron; Pearce, Kenneth L. (ed.), Idealism: New Essays in Metaphysics, Oxford University Press, 2017, ISBN 9780198746973.
  • Guyer, Paul; Horstmann, Rolf-Peter. Idealism in Modern Philosophy, Oxford University Press, 2023.
  • Neujahr, Philip J., Kant's Idealism, Mercer University Press, 1995 ISBN:0-86554-476-X
  • Prabhat Rainjan Sarkar (1984), Human Society. Vols. I and II. (Ananda Marga Publications, Calcutta, India).
  • Surendranath Dasgupta (1969), Indian Idealism (Cambridge University Press , New York, NY, USA), ISBN:0-521-09194-2
  • Sohail Inayatullah (2001), Understanding P. R. Sarkar: The Indian Episteme, Macrohistory and Transformative Knowledge, (Leiden, Brill Publishers) ISBN:90-04-12193-5.
  • Watts, Michael. Kierkegaard, Oneworld, ISBN:978-1-85168-317-8

Further reading

  • Gustavus Watts Cunningham, Idealistic Argument in Recent British and American Philosophy, Books For Libraries Press, 1967.
  • Hugh Joseph Tallon, The concept of self in British and American idealism, Catholic University of America Press, 1939.
  • Gerald Thomas Baskfield, The idea of God in British and American personal idealism, Catholic University of America, 1933.
  • Vergilius Ture Anselm Ferm, A history of philosophical systems Littlefield Adams, ISBN:0-8226-0130-3, 1968.

External links