Preface to the First Edition (1781)

Kant identifies a paradox at the core of human reason: its own nature compels it to ask questions that it cannot answer because they transcend possible experience.

Reason begins with principles validated by experience but, following its own nature, seeks ever-higher conditions, eventually invoking trans-empirical principles that cannot be tested against experience, leading to contradictions.

Kant charts metaphysics' fall from being the queen of sciences under dogmatism, through skeptical attacks, to present-day indifferentism and contempt.

Kant describes the dogmatist period of metaphysics as an absolute despotism that eventually collapsed into chaos due to its barbaric constitution.

Kant notes that Locke attempted to ground metaphysics in common experience through a 'genealogy' of understanding, but this genealogy was incorrect, and metaphysics fell back into dogmatism.

The present age exhibits indifferentism toward metaphysical inquiry, but this is not mere levity; rather, it reflects the age's mature judgment refusing illusory knowledge and preparing the ground for genuine reform.

Even those who profess indifference to metaphysics inevitably make metaphysical claims, showing that metaphysical inquiry is unavoidable for human reason.

Rather than a sign of intellectual decay, indifferentism represents matured judgment that demands reason undertake critical self-examination and establish itself on secure foundations.

Kant defines the Critical Investigation of Pure Reason as the tribunal through which reason examines its own claims according to eternal and unchangeable laws.

Kant clarifies that his critique examines the faculty of reason itself regarding cognitions it seeks without experience, aiming to determine the possibility, origin, extent, and limits of metaphysics.

Kant asserts he has discovered the cause of all errors that set reason at variance with itself in non-empirical thought and has solved them through principled examination.

Kant distinguishes his approach from dogmatism: he does not promise magical extension of knowledge beyond experience but rather destroys illusions arising from misconceptions.

Kant claims his work achieves thoroughness such that every metaphysical problem finds its solution or at least its key, based on the principle that pure reason is a perfect unity.

Kant acknowledges his declarations sound boastful but argues they are more modest than those of common dogmatists who claim to demonstrate the soul's nature or a primal being.

Rather than extending knowledge beyond experience, Kant confines himself to examining reason's pure thought, using common logic to map reason's simple operations.

Kant argues that completeness is not arbitrarily chosen but is imposed by the nature of cognition itself.

Kant identifies certitude and clearness as the two indispensable formal conditions that any critique of pure reason must satisfy.

Kant insists that in establishing a priori knowledge, opinion and hypothesis are inadmissible; everything must rest on absolute necessity.

Kant argues that determining all pure a priori cognition must provide an example of apodeictic philosophical certitude, which is both a necessary condition and a standard for the work.

Kant distinguishes between the author's task of adducing grounds and reasons and the reader's prerogative to determine their influence on the mind.

Kant highlights the second chapter's treatment of the Deduction of Pure Conceptions of Understanding as essential and laborious, necessary for understanding the understanding itself.

Kant explains that the deduction has two sides: an objective aspect demonstrating the validity of a priori conceptions, and a subjective aspect examining the faculty of thought itself.

Although the subjective deduction examining the faculty of thought is important, it is not essential to the work's main question of what and how much reason can cognize apart from experience.

The subjective deduction, as an inquiry into the cause of a given effect, appears to enounce opinion; however, Kant suggests the objective deduction alone is properly essential.

Kant identifies two kinds of clearness demanded: discursive or logical clearness based on conceptions, and intuitive or aesthetic clearness through examples.

Kant has prioritized discursive clearness as essential to his purpose, accepting the limitation that intuitive clearness through examples cannot be fully provided.

During composition, Kant recognized the task's magnitude and complexity, making it imprudent to enlarge the work with examples and illustrations.

Kant notes that the work is not for popular use and that those devoted to science do not require illustrative examples, which would interfere with the main purpose.

Kant cites Abbé Terrasson's observation that a work measured by comprehension time rather than page count reveals that many books would be shorter if not artificially shortened.

Kant argues that explanations and examples aid comprehension of parts but distract attention and prevent the reader from grasping the system's articulation and unity.

Kant appeals to readers to cooperate in erecting a complete and solid edifice of metaphysical science according to the plan presented.

Kant argues that metaphysics, as presented here, is the only science admitting of completion and can be accomplished quickly, leaving only didactic illustration to future generations.

Kant defines metaphysics as a systematic inventory of what pure reason produces from itself, which cannot remain concealed once the common principle is discovered.

The perfect unity of cognitions based on pure conceptions and free from empirical influence makes completeness both practicable and necessary.

Kant announces his intention to publish a Metaphysics of Nature that will be richer in content but shorter, applying the foundations established in the Critique.

Kant requests that readers serve as judges for the present Critique and as co-laborers in the future Metaphysics of Nature.

Although the Critique provides a complete list of principles, the Metaphysics of Nature must discover all deduced conceptions through gradual analysis of the synthesis completed in the Critique.

Kant concludes that the analytical work required for the Metaphysics of Nature will be more amusement than labor.