The Nexus Archive
German Idealism · Treatise
Prolegomena to Any Future Metaphysics
by Kant · The Judge of Reason · Enlightenment, 1724-1804
Kant's shorter doorway into the problem behind the Critique of Pure Reason.
- Advanced
- 1783
- ~3 hr 15 min read
- 18 chapter guides
- Public domain
Start reading · Read the Introduction guide free
The opening pages
Preamble: What Makes Metaphysics Distinct
§ 1. Of the Sources of Metaphysics.
IF it becomes desirable to formulate any cognition as science, it will be necessary first to determine accurately those peculiar features which no other science has in common with it, constituting its characteristics; otherwise the boundaries of all sciences become confused, and none of them can be treated thoroughly according to its nature.
The characteristics of a science may consist of a simple difference of object, or of the sources of cognition, or of the kind of cognition, or perhaps of all three conjointly. On this, therefore, depends the idea of a possible science and its territory.
First, as concerns the sources of metaphysical cognition, its very concept implies that they cannot be empirical. Its principles (including not only its maxims but its basic notions) must never be derived from experience. It must not be physical but metaphysical knowledge, viz., knowledge lying beyond experience. It can therefore have for its basis neither external experience, which is the source of physics proper, nor internal, which is the basis of empirical psychology. It is therefore a priori knowledge, coming from pure Understanding and pure Reason.
But so far Metaphysics would not be distinguish able from pure Mathematics; it must therefore be called pure philosophical cognition; and for the meaning of this term I refer to the Critique of the Pure Reason (II. "Method of Transcendentalism," Chap. I., Sec. i), where the distinction between these two employments of the reason is sufficiently explained. So far concerning the sources of metaphysical cognition.
§ 2. Concerning the Kind of Cognition which can alone be called Metaphysical.
a. Of the Distinction between Analytical and Synthetical Judgments in general.—The peculiarity of its sources demands that metaphysical cognition must consist of nothing but a priori judgments. But whatever be their origin, or their logical form, there is a distinction in judgments, as to their content, according to which they are either merely explicative, adding nothing to the content of the cognition, or expansive, increasing the given cognition: the former may be called analytical, the latter synthetical, judgments.
Analytical judgments express nothing in the predicate but what has been already actually thought in the concept of the subject, though not so distinctly or with the same (full) consciousness. When I say: All bodies are extended, I have not amplified in the least my concept of body, but have only analysed it, as extension was really thought to belong to that concept before the judgment was made, though it was not expressed; this judgment is therefore analytical. On the contrary, this judgment, All bodies have weight, contains in its predicate something not actually thought in the general concept of the body; it amplifies my knowledge by adding something to my concept, and must therefore be called synthetical.
Chapter guides · 18
Introduction
Hume Interrupts The Dogmatic Sleep
Kant asks whether reason can justify claims that go beyond what experience teaches.
Knowledge before experience
Metaphysics asks about reality through reason alone. Kant questions its claim to be a science. A priori means independent of experience. Hume asks how reason could know that one event must cause another, rather than simply expect a familiar pattern.
From Hume to a new inquiry
Kant first argues that metaphysics needs a reliable standard. He then explains how Hume changed his thinking. He expands the question from causation to all claims of necessary connections. His Critique examines the whole power of reason; the Prolegomena retraces its main steps. He closes with Virgil’s image of bees keeping idle drones away from their hive.
Preamble
Metaphysics Needs Its Own Signature
Kant separates statements that explain a concept from statements that add to our knowledge.
Two kinds of judgment
An analytical judgment brings out what a concept already contains. A synthetic judgment adds something. Kant argues that metaphysics seeks synthetic knowledge a priori: new knowledge justified independently of experience.
The Preamble’s argument
Kant begins by distinguishing metaphysics from sciences based on observation. He then uses examples from arithmetic and geometry to argue that mathematics adds knowledge rather than merely unpacking concepts. Existing metaphysical systems disagree, so none provides a secure starting point. Mathematics and pure natural science do. Their accepted results let him ask how this kind of knowledge is possible.
The General Problem
The Question Becomes Exact
Metaphysics must explain how reason can add necessary knowledge without relying on experience.
First Problem
Mathematics Constructs What It Knows
Kant grounds mathematics in the ways we perceive space and time.
Three Remarks on Space, Time, and Geometry
Ideal In Form, Real In Experience
Kant’s account of appearances preserves the reality of experience.
Second Problem
A Perception Is Not Yet Experience
A judgment about an object needs more than sensations linked in one person’s mind.
Categories and the Principles of Experience
The Tables Lock Together
Kant links the forms of judgment to the concepts and laws that make experience possible.
Nature, Experience, and the Limits of Concepts
Categories Have A Domain
The understanding supplies nature’s universal rules by making ordered experience possible.
Appendix to the Pure Science of Nature
A System Must Be Complete
Kant wants a complete system of concepts, rather than a collection that might leave something out.
Third Problem
Reason Seeks The Unconditioned
Reason seeks a completeness that no single experience can provide.
The Psychological Idea
The Self Is Not A Substance We Inspect
Awareness of ourselves does not prove that the soul must live forever.
The Cosmological Idea and Its Antinomies
Reason Divides Against Itself
Reason reaches contradictions when it treats the experienced world as a complete thing in itself.
The Theological Idea and the Work of Reason
Ideas Guide Without Describing
Ideas can guide inquiry toward a coherent whole without proving that their objects exist.
Reason at Its Bounds
A Boundary Has Two Sides
Kant places reason at a boundary: it can relate experience to an unknown ground without describing that ground.
Analogy Without Pretended Knowledge
Analogy Preserves The Relation
Kant asks what purpose our persistent metaphysical questions may serve.
Scholia
Metaphysics Must Become Critique First
Metaphysics can become a science only through a complete examination of reason’s powers and limits.
Appendix
Critical Idealism Is Not Berkeley's
Kant answers a hostile review by demanding a test of his argument.
Proposals for a Real Investigation
The Challenge Is To Do The Work
Kant invites a careful public investigation that could establish a shared standard for metaphysics.
Questions readers ask
- How long does it take to read Prolegomena to Any Future Metaphysics?
- About 3 hr 15 min in total.
- How difficult is Prolegomena to Any Future Metaphysics?
- Advanced. A mid-length treatise; about 3 hours of reading.
- Which translation is this?
- The Paul Carus translation from the German, first published in 1783. The text follows Kant's Prolegomena to Any Future Metaphysics, edited in English by Dr. Paul Carus, third edition (1912).
- Can I read Prolegomena to Any Future Metaphysics for free?
- Prolegomena to Any Future Metaphysics is part of Nexus Premium, so reading it needs an account and a Premium subscription. The opening above and two chapter guides on this page are free to read.
- How many chapter guides are there?
- 18 chapter guides, written by the Nexus editors. Two open in full here; the rest show their opening line.
About Kant
Immanuel Kant spent nearly his entire life in Königsberg, teaching and writing with remarkable regularity. His mature work attempted to explain the powers and limits of reason, while grounding morality in freedom, duty, and human autonomy.
“What must the mind contribute for experience to be possible?”
Kant changes the center of philosophy by asking not just what we know, but how knowing is possible.
Source text: public domain. Chapter guides: original Nexus writing. Prolegomena to Any Future Metaphysics is part of The Nexus Archive, guided Quests through the great works.