Classical Western Philosophy IV: Kant's Critical Philosophy and Hegel's Absolute Idealism

Kant tried to settle the quarrel between the rationalists and the empiricists by asking what the mind itself contributes to experience. The syllabus asks for the critical philosophy, the classification of judgements and the possibility of synthetic a priori judgements, the Copernican revolution, the forms of sensibility and the categories, the metaphysical and transcendental deductions, phenomenon and noumenon, the Ideas of Reason and the rejection of speculative metaphysics. Hegel then made what Kant had left as limits into moments of a single developing reality; the syllabus asks for Geist, the dialectical method, being, non-being and becoming, absolute idealism and freedom. Kant's Unit 4 moral theory is treated separately in Chapter 13.

1. The critical philosophy and the classification of judgements

Immanuel Kant (1724–1804) said Hume "interrupted my dogmatic slumber". His critical philosophy examines the powers of reason before using them: the Critique of Pure Reason (1781, second edition 1787) asks what we can know, the Critique of Practical Reason (1788) what we ought to do, and the Critique of Judgement (1790) links the two through aesthetic and teleological judgement. The guiding question of the first Critique is: how are synthetic a priori judgements possible?

Kant's classification of judgements
Source of justificationAnalytic (predicate contained in the subject)Synthetic (predicate adds to the subject)
A priori (independent of experience, necessary and universal)"All bodies are extended""7 + 5 = 12"; "every event has a cause"; "a straight line is the shortest between two points"
A posteriori (dependent on experience)None: an analytic judgement never needs experience"All bodies are heavy"; "this rose is red"

Hume had assumed that every a priori truth is analytic (relations of ideas) and every synthetic truth a posteriori (matters of fact). Kant argues that mathematics, the first principles of natural science and the claims of metaphysics are synthetic yet a priori: "7 + 5 = 12" is necessary, but the concept of 12 is not contained in the concept of the sum of 7 and 5; we reach it by constructing the sum in intuition. If such judgements are possible, the mind must supply their necessity.

ℹ️ The Copernican revolution
The preface to the second edition proposes a reversal like Copernicus's: instead of assuming that our cognition must conform to objects, assume that objects must conform to our cognition. Then a priori knowledge is possible, because we know a priori what we ourselves put into things: the forms of intuition and the categories. The price is that we know things only as they appear to us.

2. Sensibility, understanding and the deductions

Knowledge needs two faculties: sensibility, which receives intuitions, and understanding, which thinks them through concepts. "Thoughts without content are empty, intuitions without concepts are blind." The Transcendental Aesthetic shows that space (the form of outer sense) and time (the form of inner sense) are pure forms of intuition: not properties of things in themselves nor concepts drawn from experience, but the conditions under which anything can be given to us. That is why geometry and arithmetic are synthetic a priori.

The twelve categories of the understanding
GroupCategories
QuantityUnity, plurality, totality
QualityReality, negation, limitation
RelationInherence and subsistence (substance and accident), causality and dependence (cause and effect), community (reciprocity)
ModalityPossibility and impossibility, existence and non-existence, necessity and contingency
  • Metaphysical deduction: the categories are derived from the table of the logical forms of judgement (four heads, three forms each). Since every act of the understanding is a judgement, the pure concepts that correspond to these forms are the complete set of a priori concepts of objects.
  • Transcendental deduction: shows by what right the categories apply to objects of experience. "The I think must be able to accompany all my representations": the transcendental unity of apperception is the highest condition of experience, and this unity is achieved only by synthesising the manifold of intuition according to the categories. So the categories are valid of every object of possible experience, and only of such objects.
⚠️ Metaphysical versus transcendental deduction
The metaphysical deduction answers "which are the categories, and where do they come from?" (the forms of judgement). The transcendental deduction answers "by what right do they apply to objects?" (the unity of apperception). A question that mentions the "I think" wants the transcendental deduction.

3. Phenomenon and noumenon, the Ideas of Reason and the end of speculative metaphysics

Because space, time and the categories are our contribution, we know things only as phenomena, as they appear under these conditions. The thing in itself (Ding an sich), considered apart from our sensibility, is the noumenon. Kant uses the noumenon in a negative sense, as a limiting concept that marks the boundary of knowledge; it can be thought without contradiction but not known, since we have no intellectual intuition. Kant calls his position transcendental idealism and empirical realism.

The Ideas of Reason and where they fail (Transcendental Dialectic)
IdeaSpeculative scienceKant's diagnosis
The soulRational psychologyParalogisms: the formal unity of the "I think" is mistaken for a known simple, permanent substance
The world as a wholeRational cosmologyAntinomies: four pairs of opposed theses (a beginning in time or not; simple parts or not; freedom or only natural causes; a necessary being or not) each provable
GodRational theologyThe ontological, cosmological and physico-theological proofs all fail; the ontological fails because existence is not a real predicate, and the others depend on it

Reason, the faculty of principles, seeks the unconditioned and so produces the Ideas of soul, world and God, to which no intuition can correspond. Used constitutively, as if they gave knowledge of objects, they breed illusion, and that is the source of dogmatic metaphysics. Used regulatively, they are legitimate: they direct the understanding to seek ever greater unity. Speculative metaphysics as knowledge of the supersensible is therefore rejected, but God, freedom and immortality return in the practical philosophy as postulates of morality; hence Kant's remark that he "had to deny knowledge in order to make room for faith".

4. Hegel: Geist, dialectic, being and becoming, absolute idealism and freedom

G. W. F. Hegel (1770–1831; Phenomenology of Spirit, 1807; Science of Logic, 1812–16; Encyclopaedia, 1817; Philosophy of Right, 1820) makes Geist, spirit or mind, the central concept. Reality is not a fixed substance behind appearances but spirit coming to know itself through its own development in nature, history and culture. The Phenomenology traces consciousness from sense-certainty through self-consciousness (with the famous master-slave dialectic) and reason to absolute knowing. The Encyclopaedia divides spirit into subjective spirit (the individual mind), objective spirit (law, morality and ethical life: family, civil society and the state) and absolute spirit (art, religion and philosophy).

  • The dialectical method: every finite concept or form of life, thought through, generates its own contradiction and passes into its opposite; the tension is resolved in a higher unity that cancels, preserves and lifts up both, which Hegel calls Aufhebung (sublation). The development is immanent, driven by the content itself, not imposed from outside.
  • Being, non-being and becoming: the Science of Logic begins with pure being, the emptiest concept. Having no determination at all, pure being is indistinguishable from pure nothing; yet the two are also distinct. Their truth is becoming, the movement in which each passes into the other (as coming-to-be and ceasing-to-be). Becoming settles into determinate being (Dasein), and the Logic proceeds through the categories of being, essence and the concept.
  • Absolute idealism: the Absolute is the whole, and "the true is the whole"; it is to be grasped "not only as substance but equally as subject". The Philosophy of Right states "what is rational is actual, and what is actual is rational". Unlike Kant, Hegel denies an unknowable thing in itself: to draw a limit is already to be beyond it.
  • Freedom: world history is "the progress of the consciousness of freedom". In the Oriental world one was known to be free (the despot), in the Greek and Roman world some were free, and in the Germanic-Christian world all are known to be free as human beings. Freedom is realised not in arbitrary choice but in rational institutions, above all the state, which Hegel calls the actuality of concrete freedom.
⚠️ "Thesis, antithesis, synthesis" is not Hegel's formula
The triad of thesis, antithesis and synthesis comes from Fichte and was popularised as a summary of Hegel by later writers; Hegel himself hardly uses the terms and criticises the mechanical application of triads. For an exam, the dialectic is fine to describe in three moments, but a statement that Hegel "coined" the formula is false, and the technical term to know is Aufhebung.

Key takeaways

  • Kant's question: how are synthetic a priori judgements possible? Analytic judgements are a priori; "7 + 5 = 12" and "every event has a cause" are synthetic a priori; the Copernican revolution makes objects conform to cognition.
  • Space and time are pure forms of intuition; twelve categories under quantity, quality, relation and modality; the metaphysical deduction derives them from the forms of judgement, the transcendental deduction justifies them through the unity of apperception.
  • We know phenomena, not noumena; the Ideas of soul, world and God yield paralogisms, antinomies and failed proofs when used constitutively; they are regulative only, and return as postulates of practical reason.
  • Hegel: Geist as reality coming to know itself; subjective, objective and absolute spirit; dialectic as immanent development through Aufhebung (the "thesis-antithesis-synthesis" label is Fichte's).
  • Hegel: pure being and nothing pass into becoming; the true is the whole; the rational is actual; history is the progress of the consciousness of freedom (one, some, all).

Practice questions (10)

Attempt each one before opening the answer. Every explanation names the tempting wrong option as well as the right one, because that is where marks are lost.

  1. For Kant, space and time are:

    1. Categories of the understanding
    2. Pure forms of sensible intuition
    3. Ideas of reason
    4. Properties of things in themselves
    Show answer

    Answer: B — Pure forms of sensible intuition

    The Transcendental Aesthetic makes space the form of outer sense and time the form of inner sense. The categories belong to the understanding, the Ideas (soul, world, God) to reason, and Kant denies that space and time are properties of things in themselves.

  2. Which of the following is, for Kant, a synthetic a priori judgement?

    1. All bachelors are unmarried
    2. All bodies are heavy
    3. All bodies are extended
    4. Every event has a cause
    Show answer

    Answer: D — Every event has a cause

    "Every event has a cause" is necessary and universal, but the concept of a cause is not contained in the concept of an event. "All bodies are extended" and "all bachelors are unmarried" are analytic; "all bodies are heavy" is Kant's example of a synthetic a posteriori judgement.

  3. Under which heading of Kant's table does the category of causality fall?

    1. Relation
    2. Quality
    3. Quantity
    4. Modality
    Show answer

    Answer: A — Relation

    Relation contains substance and accident, cause and effect, and community. Quantity has unity, plurality and totality; quality reality, negation and limitation; modality possibility, existence and necessity with their opposites.

  4. In Hegel's Science of Logic, the truth of pure being and pure nothing is:

    1. Substance
    2. The Absolute Idea
    3. Becoming
    4. Essence
    Show answer

    Answer: C — Becoming

    The Logic opens with being, nothing and becoming: indeterminate being is indistinguishable from nothing, and their truth is the movement of each into the other, becoming. Essence is the second main division of the Logic, and the Absolute Idea its end.

  5. The argument that the "I think" must be able to accompany all my representations belongs to Kant's:

    1. Metaphysical deduction
    2. Antinomies of pure reason
    3. Transcendental Aesthetic
    4. Transcendental deduction
    Show answer

    Answer: D — Transcendental deduction

    The transcendental unity of apperception is the centre of the transcendental deduction, which justifies applying the categories to objects. The metaphysical deduction derives the categories from the forms of judgement, the Aesthetic treats space and time, and the antinomies belong to the Dialectic.

  6. Assertion (A): Kant holds that the noumenon cannot be known. Reason (R): Human beings have no intellectual intuition; all our intuition is sensible. Choose the correct option.

    1. Both A and R are true, and R is the correct explanation of A
    2. Both A and R are true, but R is not the correct explanation of A
    3. A is true, but R is false
    4. A is false, but R is true
    Show answer

    Answer: A — Both A and R are true, and R is the correct explanation of A

    Both are true and R explains A. Knowledge needs intuition plus concepts; our only intuition is sensible and gives things as they appear, so the thing in itself can be thought but not known.

  7. Assertion (A): Hegel's dialectic moves through Aufhebung, in which a contradiction is resolved in a higher unity. Reason (R): Hegel introduced the formula "thesis, antithesis, synthesis" and used it throughout his works. Choose the correct option.

    1. Both A and R are true, and R is the correct explanation of A
    2. Both A and R are true, but R is not the correct explanation of A
    3. A is true, but R is false
    4. A is false, but R is true
    Show answer

    Answer: C — A is true, but R is false

    A is true: Aufhebung cancels, preserves and lifts up the opposed moments. R is false: the triadic formula is Fichte's and was attached to Hegel later; Hegel rarely used it and criticised mechanical triads.

  8. Which of the following are Ideas of Reason in Kant's Transcendental Dialectic? Select all that apply.

    1. The soul
    2. God
    3. Causality
    4. The world as a whole
    Show answer

    Answer: A — The soul; B — God; D — The world as a whole

    The three Ideas are soul, world as a whole and God, examined in the paralogisms, antinomies and ideal of pure reason. Causality is a category of the understanding and does apply to objects of experience.

  9. Which of the following belong to absolute spirit in Hegel's system? Select all that apply.

    1. Religion
    2. Philosophy
    3. Art
    4. The state
    Show answer

    Answer: A — Religion; B — Philosophy; C — Art

    Absolute spirit is art, religion and philosophy, in which spirit knows itself. The state, with the family and civil society, belongs to ethical life within objective spirit.

  10. How many categories are there in Kant's table of the categories? Type the number.

    Numerical answer — type the value.

    Show answer

    Answer: 12

    Twelve: four headings (quantity, quality, relation, modality) with three categories under each, matching the twelve logical forms of judgement.