Relation to the world· Mind and consciousnessdifficulty
Nature of reality
What is reality made of: matter, mind, or both?
What, at bottom, is the world made of? To say that everything is matter, that everything is mind, or that reality comprises two irreducible orders is to set the background for everything else: what God, life, and thought are, and what an understanding of the world can hope to achieve. The question is the oldest and most abstract in metaphysics, yet every worldview answers it, often without realizing it.
Materialism
9Everything that exists is material, including thought, which is merely a product of how matter is organized. Mind is not a separate substance: it can be fully explained by the body and the brain.
Explore this position →Epicurusexplicit
All that exists reduces to atoms and void: nothing comes from non-being, nothing dissolves into it, the whole is body and space. The soul itself is made of very fine atoms and dissolves at death. This is a thoroughgoing materialism, inherited from and developed by , with no room for any immaterial reality.
Letter to Herodotus, 39-44 (atoms and void, nothing comes from nothing) · Lucretius, On the Nature of Things, I-II
Lucretiusexplicit
Everything begins from two principles that establishes before all else: nothing comes from nothing, nothing returns to nothing. Were it otherwise, anything could spring from anything, with no seed and no season; yet experience shows fixed natures and ordered cycles, so the real reduces to first bodies, the atoms, and the void that lets them move. Outside this pair nothing exists in itself: soul and mind themselves are aggregates of very fine atoms, and there is no room for any immaterial substance. This thoroughgoing materialism, inherited from and , Lucretius unfolds into a complete system and makes visible, from the speck of dust dancing in a sunbeam to the infinity of worlds.
On the Nature of Things, I, 146-264 (nothing from nothing, nothing to nothing) · On the Nature of Things, I, 418-448 (the all is body and void)
Epicureanismexplicit
Two sure principles govern the whole physics: nothing comes from nothing and nothing returns to nothing, and the very motion of bodies proves there is void in which they move. From this it follows that there exist only atoms, full and indivisible particles, and the void that separates them: everything else, qualities, souls, gods, is but a transient arrangement of these grains. The stake is not speculative but liberating: if the soul itself is an aggregate of atoms that dissolves at death, then the afterlife, judgment and providence collapse at a stroke, and with them the two great fears. This materialism, taken from Democritus but redirected toward happiness, stands squarely against the Stoics' cosmos animated by a and against 's world of Forms.
Epicurus, Letter to Herodotus, 38-44 · Lucretius, On the Nature of Things, book I
Marxexplicit
To explain an age, one must start not from what it says of itself but from how men produce their material life: it is this reversal of the order of explanation that governs everything. Where made the real subject of history and concrete conditions its mere manifestations, Marx claims to turn the dialectic, standing on its head, the right way up, on its feet: social being, the totality of the relations of production, is the real base of which ideas, law and religion are the superstructure. Yet this materialism is not the contemplative mechanism of earlier materialists, whom he faults precisely for ignoring human activity, hence an overwhelming weight to materialism with a residual share.
Capital, vol. I, afterword to the 2nd edition (the dialectic set on its feet) · The German Ideology, I (the materialist conception of history)
Marxismexplicit
The starting point is not an idea but a fact: humans must first produce their means of subsistence before they can think, pray, or legislate. From this Marx "inverts" 's dialectic, in which Spirit unfolded itself in the world: it is not the idea that begets the real, but material activity that begets ideas. Law, religion, and philosophy become superstructures, reflections of the economic base and not first causes. The target is not only but every idealism that believes it can change the world by changing ideas: for Marx, that is to mistake the reflection for the source.
Marx and Engels, The German Ideology (1845-1846) · Engels, Ludwig Feuerbach and the End of Classical German Philosophy (1888)
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Nietzscheinferable
The critique of "hinterworlds" and the call to remain faithful to the earth bring everything back to sensuous : the body, forces, this world. Without subscribing to a mechanistic materialism he also mocks, Nietzsche refuses any true world behind the phenomenon, which places him on the side of a this-worldly ontology rather than idealism.
Twilight of the Idols, "How the True World Finally Became a Fable" · Thus Spoke Zarathustra, Prologue, §3
Stoicismexplicit
Stoic physics is corporealist: only what acts or is acted upon exists, and only bodies can do so. Even the soul and the divine are corporeal, made of a subtle breath, the pneuma. This is a materialism, though one infused with internal reason, which sets Stoicism apart from Platonic idealism.
Diogenes Laertius, Lives, VII, 134-135 · Seneca, Letters to Lucilius, 65
Senecainferable
The Stoic physics Seneca expounds in the Natural Questions is corporealist: only what acts or is acted upon exists, hence only bodies. The active principle itself, the divine reason (), is a material breath (pneuma) diffused through the world, placing his metaphysics on the materialist side, with only a slight surface soul-body dualism.
Natural Questions, II (the corporeal nature of the active principle) · Letters to Lucilius, CVI and CXVII (only bodies exist)
Taoisminferable
Taoist cosmology resists reduction to Western categories: reality is a continuous flux of qi 氣 (the breath, the energy animating all things), with no sharp break between matter and mind, which places Taoism closer to a monism of materialist coloring than to idealism or dualism. The , the undifferentiated source from which the One, then the Two, then the ten thousand things arise, is neither pure spirit set apart from matter nor an individual mind: everything proceeds from a single energetic ground.
Laozi, Dao De Jing, ch. 42 · Zhuangzi, ch. 22 (Knowledge Wandered North)
Idealism
14At bottom, the real is not matter but idea: intelligible realities, which thought alone can grasp, make things what they are. Depending on the version, the sensible world participates in essences that exist independently of our minds, unfolds a thought that realizes itself in it, or exists only for a mind that perceives it. Matter, far from being primary, depends on it.
Explore this position →George Berkeleyexplicit
Berkeley starts from a simple empiricist remark: whatever I have an idea of, I have it through the senses, hence as a perception. But to posit, behind my perceptions, a matter that would exist without being perceived is to posit the idea of a thing of which, by definition, I can have no idea: a contradiction. He thus turns 's empiricism against matter itself: what we call bodies is only an ordered collection of sensible ideas, and for them to exist is to be perceived. What remains is that which perceives, the mind, the one genuine substance. Far from denying the world, he claims to save it from scepticism by removing the veil of an unknowable matter set between us and it.
Principles of Human Knowledge, §§3-7 · Three Dialogues between Hylas and Philonous, I
Hegelexplicit
The true cannot be thought as inert matter that mind would observe from outside: it must be grasped also as subject. The real is the Idea that unfolds, externalizes itself, then returns to itself in knowing itself; its structure is rational, and matter has truth only through the thought that runs through it. Whether the reach of this idealism is cosmic or merely logical still divides readers.
Phenomenology of Spirit, Preface · Science of Logic, Doctrine of the Concept
Śaṅkaraexplicit
A single reality exists without a second, , pure consciousness: neither matter nor the plurality of things are autonomous substances. The world of objects is not sheer nothingness, but it holds only an empirical reality (vyāvahārika), superimposed on brahman by ignorance, as one sees a snake where there is only a rope. This idealism is sui generis: it does not make the world the content of a finite mind, in 's manner, but refers it wholly to the one absolute consciousness of which things are merely the appearance. The question is thus not "mind or matter?" but "is the manifold real?", to which Śaṅkara answers by non-duality.
Commentary on the Brahma Sūtras, I.1.1-4 · Upadeśasāhasrī
German Idealismexplicit
German Idealism carries to its summit: the ground of the real is not matter but mind. Yet it is no longer the idealism of a , for whom things exist only insofar as they are perceived by finite minds: it is an absolute idealism, in which nature and history are the moments of one and the same Spirit that thinks itself and recognizes itself in its other. posits the identity of nature and mind; makes substance a subject.
Hegel, Phenomenology of Spirit (Preface) · Schelling, System of Transcendental Idealism
Schopenhauerexplicit
The first book of begins from a radicalized Kantian premise: the world exists only as , under the a priori forms of space, time, and causality. But where left the unknowable, Schopenhauer holds that we have a unique access to it: our body, known from without as representation and from within as will. Materialism is refuted as the philosophy 'of the subject that forgets itself in its own reckoning'; his idealism nonetheless remains singular, since the ground of the real is not mind but blind willing.
The World as Will and Representation, Book I, §1
Leibnizexplicit
Whatever is composite presupposes something simple, for an aggregate borrows its reality from its elements: there must therefore exist simple substances, without parts, the monads. But matter, endlessly divisible and extended, is never simple: the true atoms of nature cannot be material but must be of a spiritual order, units whose essence is perception and appetition. Extended matter then has only a derived reality, that of a well-founded phenomenon resulting from the aggregation of monads. This answers the problem of the unity of the real that Cartesian extension, always divisible, could not ground; it keeps a dualist tint, the order of bodies and that of souls remaining distinct but harmonized.
Monadology, §1-7 (the monads, simple windowless substances) · Letters to De Volder and Des Bosses (well-founded phenomena)
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Platonismexplicit
Reality is measured by the stability of being: what stays self-identical is more real than what wavers between being and non-being. Now the sensible, always in becoming, has only a borrowed being, held by participation (the relation by which the sensible derives its being from the intelligible) in the intelligible that grounds it. Hence a hierarchical dualism (the division of the real into two orders, the intelligible and the sensible, soul and body), two worlds but not on a par: the sensible is the shadow, the intelligible the source. The allegory of the cave turns this into an argument about the human condition, prisoner of copies until it has converted its gaze. Against materialism, it is not the body that grounds the soul, but the intelligible that grounds the sensible.
Plato, Republic, 514a-517a, allegory of the cave · Plotinus, Enneads, V
Vedānta (Advaita)explicit
The criterion of the real, for Advaita, is permanence: only what is never contradicted across states and resolves into nothing else is fully real. But every plural thing arises, changes and passes, and the experience of waking dissolves the dream-world as waking dissolves illusion: plurality therefore has only an empirical, dependent reality, superimposed by avidyā upon (the absolute, being-consciousness-bliss, sat-cit-ānanda) alone, which remains self-identical. Against the dualism of Sāṅkhya, which posits two irreducible principles, spirit (puruṣa) and nature (prakṛti), Advaita refuses any ultimate duality: there are not two reals but one, of which matter is only the appearing. And against the materialist it objects that the consciousness which attests every thing cannot itself be one material object among others.
Śaṅkara, Commentary on the Brahma-Sūtras (Brahma-Sūtra-Bhāṣya), I · Chāndogya Upaniṣad, VI
Kantexplicit
If the mind conformed to objects, we could never know anything of them a priori; reverse the hypothesis, as Copernicus set the observer at the centre, and let objects conform to our cognition. Then space, time and the categories are not features of things but the forms of the subject under which alone an object can appear to us. The consequence is transcendental idealism: we know only phenomena, never the . This boundary saves science (its laws hold necessarily for every phenomenon) without collapsing into 's idealism, since the thing in itself remains; the phenomenon / noumenon dualism thus kept rules out the fully idealist pole.
Critique of Pure Reason, Transcendental Aesthetic · Prolegomena to Any Future Metaphysics, §13
Platoexplicit
The argument starts from a premise inherited from Heraclitus: the sensible is in perpetual flux, and of what never ceases to become there can be no science. Yet since we do know the equal, the just, the circle, there must exist stable, intelligible objects of which sensible things are only imperfect reflections: this is the higher degree of reality. The allegory of the cave, where prisoners take shadows for the real, dramatizes this . A dualism Plato never dissolves remains, two distinct orders held side by side, whose relation of "participation" stays problematic, as he himself concedes in the Parmenides.
Republic, VII, 514a-518b (allegory of the cave) · Timaeus, 27d-29d
Plotinusexplicit
The real unfolds as a hierarchy of degrees of being, from the down to matter: the more a thing is one and intelligible, the more real it is; the more dispersed in the sensible, the less. The sensible world is therefore not illusory but the lowest degree, a faint image produced by the that orders and animates the cosmos. Matter, at the bottom of the scale, is all but nothing, sheer lack. This priority of mind leans strongly toward idealism, but it is a Platonic gradation, not the idealism of a for whom to be is to be perceived: a duality of intelligible and sensible persists, hence a residual weight on dualism.
Enneads, V, 1 and V, 2 · Enneads, IV, 8 (On the Descent of the Soul into Bodies)
Charles Sanders Peirceextrapolated
In his late, speculative metaphysics Peirce calls himself an : the one intelligible theory of the universe makes matter an effete mind, habits grown so inveterate as to become physical laws. This is neither the materialism that reduces mind to matter, nor 's subjective idealism for which the world exists only as perceived: mind here is primary and objective, and continuity () forbids separating the two into substances. The position stays fragile, stated in programmatic, unfinished texts, hence an extrapolated status.
The Architecture of Theories (1891)
Husserlinferable
After the reduction, Husserl holds that all objectivity is constituted by transcendental consciousness: the world has meaning and validity of being only as the correlate of the acts that intend it, never as an absolute reality posited outside them. This is a , but one to be carefully distinguished from 's: it does not deny the world's existence nor dissolve it into sensations in a mind; it analyses how the world gives itself and makes sense for a consciousness. The real is no illusion, it is what is constituted in and for subjectivity; a measure of realism remains, since the perceived thing keeps its transcendence over against consciousness, always given by profiles, never exhausted.
Ideas I, §49-55 · Cartesian Meditations, Fourth Meditation
Romanticisminferable
For German philosophical Romanticism, spirit is primary and nature is its visible manifestation: far from being dead matter, the world is the work and the mirror of a spiritual activity that seeks itself in unfolding. posits the identity of spirit and nature in the absolute, and makes imagination the power that constitutes the real as much as it discovers it.
Schelling, System of Transcendental Idealism · Novalis, Fragments
Dualism
7Reality comprises two irreducible orders: matter, extended and measurable, and mind, immaterial and conscious. Neither reduces to the other, even though they meet in us, where body and thought interact.
Explore this position →Descartesexplicit
Reality divides into two irreducible substances: the thinking thing (res cogitans), whose essence is thought, and the extended thing (res extensa), whose essence is geometrical extension. This is Cartesian dualism, which grounds the possibility of an entirely material physics and an immaterial soul.
Meditations on First Philosophy, VI · Principles of Philosophy, I, arts. 51-54
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Thomas Aquinasinferable
Thomas is neither a materialist, the real including spiritual substances (God, the angels, the intellective soul), nor an idealist, the sensible world having a consistency of its own. His position approaches a moderate dualism: the human creature is composed of a material body and a subsistent spiritual soul, but this dualism is tempered by the hylomorphic unity, which refuses to treat the human being as two juxtaposed substances, as later would.
Summa Theologiae, Ia, q. 75-76
Lockeinferable
Locke admits a bodily reality endowed with primary qualities (extension, figure, motion) that our ideas copy, but also a thinking mind; and he confesses he cannot know whether God might not have given matter the power to think. This cautious dualism of body and mind, alongside a solid realism of bodies, rules out both idealism and strict materialism, hence weights shared between materialism and dualism.
Essay Concerning Human Understanding, II, ch. 8 (primary and secondary qualities) and IV, ch. 3, §6 (thinking matter)
Beauvoirextrapolated
Beauvoir elaborates no systematic metaphysics, but her existentialist-inflected phenomenology presupposes a primary material and bodily reality, grasped through the consciousness that gives it meaning. The body, neither pure thing nor pure idea, is lived as situation, which forbids ranging her squarely under materialism or idealism.
The Second Sex (1949), "The Data of Biology" and the body as situation
Sartreinferable
The ontology of Being and Nothingness sets two regions of being against each other: the in-itself, full, opaque, what it is, and the for-itself, consciousness, a nothingness that brings forth the world and its meanings. This is not a substance dualism in 's manner, since the for-itself is no thinking thing but a fissure in being; nor is it a materialism, consciousness not being reducible to the in-itself. The position stands between a basis of brute being and the irreducibility of conscious upsurge, hence the shared weights.
Being and Nothingness, Introduction (the in-itself and the for-itself)
Humeinferable
Hume suspends every strong thesis about the ultimate nature of the real: he treats as a fiction both the belief in the continued, independent existence of bodies and the belief in a spiritual substance, without denying either in ordinary life. This about substance, material or immaterial, forbids any clear classification and yields near-balanced weights, with a slight tilt toward the dualist doubt inherited from his examination of perceptions.
A Treatise of Human Nature, I, part IV, sect. 2 (of scepticism with regard to the senses) · A Treatise of Human Nature, I, part IV, sect. 5 (of the immateriality of the soul)
Spinozainferable
Spinoza is a monist: a single substance, God or Nature, of which thought and extension are two attributes expressing the same reality under two aspects (the order and connection of ideas is the same as the order and connection of things). His position therefore fits none of the three slots: it stands at the centre, neither materialist (extension is not primary) nor idealist (nor is thought), and its dualism of attributes is not a dualism of two substances. Hence near-equal weights.
Ethics, II, prop. 7 (parallelism of ideas and things) · Ethics, I, def. 4 and prop. 14 (the attributes of the single substance)
See the problem map in the Atlas →
Related problems to broaden toward other axes
- DescriptiveThe world, or our representations?
Even granting our perceptions are coherent, do they reach things as they are, or only our representations, with no way to compare the two?
the external worldRelation to certainty
This dwelling is the prison; the light of the fire in it is the sun; and the upward journey is the ascent of the soul into the intelligible region.Plato · Republic, VII, 517b
To them, would not the truth be literally nothing but the shadows of the artificial objects?Plato · Republic, VII, 515c
Brahman is real, the world is appearance, and the self is nothing other than brahman.Śaṅkara · verse attributed to Śaṅkara (Brahmajñānāvalīmālā)
The world is my representation.Schopenhauer · The World as Will and Representation, Book I, §1
The totality of things is made of bodies and void.Epicurus · Letter to Herodotus, 39
The monads have no windows through which anything could enter or leave.Leibniz · Monadology, §7
Their being is to be perceived; nor is it possible they should have any existence out of the minds which perceive them.George Berkeley · Principles of Human Knowledge, §3
Nothing is ever created out of nothing by divine power.Lucretius · On the Nature of Things, I, 150
Everything turns on grasping and expressing the true not only as substance, but equally as subject.Hegel · Phenomenology of Spirit, Preface