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I presented Kant's Vision & Mission [ What can I know, do and hope for] are covered within his 3 main Critiques & others.
To understand Kant's overall theme, one need to cover all the above 3 critiques in details plus other relevant books/articles from Kant.
The most critical of Kant's philosophical element is that of his Critique of Metaphysics in the Transcendental Dialectic [logic of illusions] [1c].

1. Critique of Pure Reason -CPR
-a. Sensibility
-b. Understanding [intellectuality]
-c. Reason [Dialectic] - Metaphysics
2. Critique of Practical Reason - CPrR
-a. Metaphysics of Moral
-b. Groundwork for the Metaphysics of Morals
3. Critique of Judgment -CoJ

Here is an article from SEP which I believe is a good representative of Kant's Critique of Metaphysics. I am only presenting Section 1 and 2 of the article. The rest Section3-6 can be read from the SEP link. See Kant's definition of 'Metaphysics' later post.

Kant's Critique of Metaphysics focus on determining whether the noumenon, thing-in-itself, soul, immortality, freedom, the whole World, God can be conventionally 'real' or not.
The answer is a categorically NO!

Whilst Kant critiqued Metaphysics as ultimately illusory [not real], it is nevertheless a VERY necessary and useful illusion for the progress of science and morality.

The following is an article that explains the above.

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Kant’s Critique of Metaphysics: Michelle Grier
https://plato.stanford.edu/entries/kant-Metaphysics/#:

Introduction
How are synthetic a priori propositions possible?
This question is often times understood to frame the investigations at issue in Kant’s Critique of Pure Reason. [with emphasis on the metaphysics]

This relation between Intuitions, Concepts and the Presentation of Concepts to the Intuition through Imagination is the answer to the question of how Synthetic a priori Judgements are possible,

In answer to it, Kant saw fit to divide the question into three:
1) How are the synthetic a priori propositions of mathematics possible?
2) How are the synthetic a priori propositions of natural science possible? Finally,
3) How are the synthetic a priori propositions of Metaphysics possible?

[the question is, if scientific and mathematical propositions are 'real' can metaphysical claims like nuomenon, thing-in-itself, soul, the-World, and God be as real?]

In Systematic fashion, Kant responds to each of these questions.
The answer to question one [Mathematics] is broadly found in the Transcendental Aesthetic, and the doctrine of the Transcendental Ideality of Space and Time.
The answer to question two [re Science] is found in the Transcendental Analytic [Understanding [intellect]], where Kant seeks to demonstrate the essential role played by the Categories in grounding the possibility of knowledge and experience.

The answer to question three [Metaphysics] is found in the Transcendental Dialectic [logic of illusions], and it is a resoundingly blunt conclusion:
the synthetic a priori propositions that characterize Metaphysics are not really possible at all.

Metaphysics, that is, is inherently Dialectical [illusory].
Kant’s Critique of Pure Reason is thus as well known for what it rejects as for what it defends.
Thus, in the Dialectic [logic of illusion], Kant turns his attention to the central disciplines of traditional, rationalist, Metaphysics —
i. Rational Psychology, [the Soul]
ii. Rational Cosmology [the Universe], and
iii. Rational Theology [God].
Kant aims to reveal the errors that plague each of these fields.

His [Kant’s] Dialectic [logic of illusion] no longer offers Rules for executing convincing Judgements, but teaches how to detect and uncover Judgements which bear a semblance of truth but are in fact illusory.
“WE have already entitled “dialectic”-in-general a Logic of Illusion.” [B297]

1. Preliminary Remarks: The Rejection of Ontology (general Metaphysics); and the Transcendental Analytic

Despite the fact that Kant devotes an entirely new section of the Critique to the branches of special Metaphysics, his criticisms reiterate some of the claims already defended in both the Transcendental Aesthetic and the Transcendental Analytic.
Indeed, two central teachings from these earlier portions of the Critique —
1. the Transcendental Ideality of Space and Time, and
2. the critical limitation of all application of the concepts of the Understanding [intellect] to “appearances” —
already carry with them Kant’s rejection of “ontology (metaphysica generalis)” or [General Metaphysics].

Accordingly, in the Transcendental Analytic Kant argues against any attempt to acquire knowledge of “objects-in-general” through the formal concepts and principles of the Understanding [intellect], taken by themselves alone.

In this connection, Kant denies that
the principles or rules of
either general logic (e.g., the principle of contradiction),
or those of his own “Transcendental Logic” (the Pure Concepts of the Understanding [intellect]) by themselves yield knowledge of objects.

These claims follow from Kant’s well-known “kind distinction” between the Understanding [intellect] and Sensibility, together with the view that knowledge requires the cooperation of both faculties.
This position, articulated throughout the Analytic, entails that independently of their application to intuitions,
the concepts and principles of the Understanding [intellect] are mere Forms of thought which cannot yield knowledge of objects.

For if no intuition could be given corresponding to the concept,
the concept would still be a thought [only], so far as its form is concerned,
but would be without any object,
and no knowledge of anything would be possible by means of it.
So far as I could know, there would be nothing, and could be nothing, to which my thought could be applied. B146

We thus find one general complaint about efforts to acquire metaphysical knowledge:
the use of formal concepts and principles, in abstraction from the sensible conditions under which objects can be given, cannot yield knowledge.

Hence, the “Transcendental” use of the Understanding [intellect] (its use independently of the conditions of Sensibility) is considered by Kant to be Dialectical [leads to illusions],
to involve erroneous applications of concepts
in order to acquire knowledge of things independently of Sensibility/experience.

Throughout the Analytic Kant elaborates on this general view, noting that the Transcendental employment of the Understanding [intellect], which aims towards knowledge of things independently of experience (and thus knowledge of “noumena”), is illicit (cf. A246/B303).

It is in this connection that Kant states, famously, in the Analytic, that
“…the proud name of ontology [general metaphysics], which presumes to offer synthetic a priori cognitions of things-in-general… must give way to the more modest title of a Transcendental Analytic” (cf. A247/B304).

Nb: Ontology [traditional] in this case refer to the claim of things-in-themselves existing regardless of whether there are human or not. Ontology in this case is not tenable for synthetic a priori cognitions which is only possible within Transcendental Analytic.

Filling this out, Kant suggests that to take ourselves to have unmediated intellectual access to objects (to have “non-sensible” knowledge) correlates with the assumption that there are non-sensible objects that we can know.
To assume this, however, is to conflate “phenomena” (or appearances) with “noumena” (or things-in-themselves).

The failure to draw the distinction between appearances and things-in-themselves is the hallmark of all those pernicious [having a harmful effect, especially in a gradual or subtle way] systems of thought that stand under the title of “Transcendental Realism.” [aka philosophical realism - absolute mind independence]
Kant’s Transcendental Idealism [philosophical antirealism] is the remedy for these.
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Discuss??
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2. The Rejection of Special Metaphysics; and the Transcendental Dialectic

Kant’s rejection of the more specialized branches of Metaphysics is grounded in part on this earlier claim, to wit,
that any attempt to apply the concepts and principles of the Understanding [intellect] independently of the conditions of Sensibility (i.e., any Transcendental use of the Understanding [intellect]) is illicit.

Thus, one of Kant’s main complaints is that metaphysicians seek to deduce a priori synthetic knowledge simply from the unschematized (pure) Concepts of the Understanding [intellect] [Categories].
The effort to acquire metaphysical knowledge through concepts alone, however, is doomed to fail, according to Kant, because (in its simplest formulation) “concepts without intuitions are empty” (A52/B76).

Although this general charge [doomed to fail] is certainly a significant part of Kant’s complaint, the story does not stop there.
In turning to the specific disciplines of special Metaphysics (those concerning the Soul, the World, and God), Kant devotes a considerable amount of time discussing the human interests [the Metaphysical urge, propensity, drive, proclivity] that nevertheless pull us into the thorny questions and controversies that characterize special Metaphysics.
These [human] interests are of two types, and include
1.theoretical goals of achieving completeness and Systematic Unity of knowledge, and
2. practical interests in securing the immortality of the Soul, freedom, and the Existence of God. [for purpose of morality]

Despite their contributions to metaphysical illusion, Kant tells us that the goals and [human] interests in question are unavoidable, inevitable, and inherent in the very nature of human Reason.
In the Introduction to the Transcendental Dialectic [illusion] Kant thus introduces “Reason” as the locus of these metaphysical interests.

2.1 The Theory of Reason and Transcendental Illusion
The emphasis on Reason in this connection is important, and it links up with the project of Kant’s “Critique” of Pure Reason [CPR].
A major component of this critique [CPR] involves illuminating the basis in Reason for our [naturally driven] efforts to draw erroneous metaphysical conclusions (to employ concepts “Transcendentally”), despite the fact that such use has already been shown (in the Transcendental Analytic) to be illicit.

What emerges in the Dialectic [illusory] is a more complex story, one in which Kant seeks to disclose and critique the “Transcendental ground” that leads to the misapplications of thought which characterize specific metaphysical arguments.
In developing the position that our metaphysical propensities are grounded in the “very nature of human Reason,” Kant (in the Introduction to the Dialectic) relies on a conception of Reason as a capacity for syllogistic Reasoning.
This logical function of Reason resides in the formal activity of subsuming propositions under ever more general principles
in order to systematize, unify, and “bring to completion”
the knowledge given through the real use of the Understanding [intellect] (A306/B363-A308/B365).

Kant thus characterizes this activity as one which seeks “conditions” for everything that is conditioned.
It is therefore central to this Kantian conception of Reason that it is preoccupied with the
“Unconditioned which would stop the regress of conditions
by providing a condition that is not itself conditioned in its turn.”

The demand for the Unconditioned is essentially a demand for ultimate explanation, and links up with the rational prescription to secure Systematic Unity and completeness of knowledge. [a psychological drive]
Reason, in short, is in the business of ultimately accounting for all things.

As Kant formulates this interest of Reason in the first Critique, it is characterized by the logical maxim or precept:
“Find for the conditioned knowledge given through the Understanding [intellect]
the Unconditioned whereby its Unity is brought to completion” (A308/B364). P1

It is central to Kant’s Dialectic that this requirement for Systematic Unity and Completeness of knowledge is inherent in the very nature of our Reason.

Controversially, Kant does not take it that this demand for the Unconditioned is something we can dismiss, [it is an unavoidable instinct]
nor does he take the interests we have in Metaphysics to be merely products of misguided enthusiasm.

Although the demand for the Unconditioned is inherent in the very nature of our Reason,
although it is unavoidable and indispensably necessary,
Kant nevertheless does not take it to be without problems of a unique sort;
for the very same demand that guides our rational scientific inquiries and defines our (human) Reason
is also the locus of error that needs to be curbed or prevented.

In connection with this principle, then, Kant also identifies Reason as the seat of a unique kind of error,
one that is essentially linked up with metaphysical propensities, and one which he refers to as “Transcendental Illusion [transzendentale Illusion].”
Kant identifies Transcendental Illusion with the propensity to
“take a subjective necessity of a connection of our concepts…for an objective necessity in the determination of things-in-themselves” (A297/B354).

Very generally, Kant’s claim is that it is a peculiar feature of Reason that it unavoidably takes its own subjective interests and principles to hold “objectively.”
And it is this propensity [natural drive], this “Transcendental Illusion,” according to Kant, that paves the way for Metaphysics.

Reason plays this role by generating principles and interests [God, Freedom, immortal Soul] that incite us to defy the limitations of knowledge already detailed in the Transcendental Analytic.
The Introduction to the Transcendental Dialectic is therefore interesting for Kant’s presentation of Reason as a presumably distinct capacity for cognizing in a way that, as Kant puts it,
incites us to tear down the boundaries already enforced in the Analytic [Understanding [intellect]] (cf. A296/B352).
Kant refers to this capacity of Reason [to tear down boundaries in Analytic ..] as one that leads to the specifically Transcendent Judgments that characterize Metaphysics.
Thus, the Transcendental Dialectic is said to be concerned “to expose the illusion in Transcendent Judgments” (A297/B354).
Indeed, Dialectic is defined as “the logic of illusion [Schein]” (A293/B350).

The central problem is that
the above prescription to seek the Unconditioned presents to Reason as a metaphysical principle
that tells us that the Unconditioned is already given, and is (as it were) “there” to be found.

This Problematic Principle is formulated by Kant as follows:
“If the conditioned is given, the absolutely Unconditioned… is also given” (A308/B366). [should be A308 B304 - P2]

if the Conditioned is Given,
the whole Series of Conditions, subordinated to one another -- a Series which is therefore itself Unconditioned –
is likewise Given, that is, is contained in the Object and its Connection. (P2) A308 B304

This “Supreme Principle of Pure Reason” [P2]
provides the background assumption under which the metaphysician proceeds.
These claims set the agenda for Kant’s project, which involves showing
1. not simply that the metaphysical arguments are fallacious,
2. but also exposing their source in Reason’s more general illusions.

Kant has been traditionally taken to be offering a method of avoiding the insidious “Transcendental Illusion” that gives rise to Metaphysics.
Read in this way, Kant’s Dialectic offers a criticism
not only of the specific arguments of Metaphysics,
but also of Transcendent, metaphysical (speculative or theoretical) interests and propensities themselves. [the natural inevitable, inherent drives of Reason]
This certainly accords with much in the Dialectic, and specifically with Kant’s well-known claim that knowledge has to be limited to possible experience.

Kant, however, complicates things somewhat by also stating repeatedly that the illusion that grounds Metaphysics (roughly, that the Unconditioned is already given) is unavoidable.
Moreover, Kant sometimes suggests that such illusion is somehow necessary for our epistemological projects (cf. A645/B673).
In this connection, Kant argues that the Transcendent Ideas and Principles of Reason do have a positive role to play in knowledge acquisition, so long as they are construed “regulatively” and not “constitutively.”

He thus suggests that rather than jettison the Ideas of metaphysical objects (something, it seems, he does not think we are in a position to do),
it is best to identify the proper use and function of these Ideas and principles.

This critical reinterpretation involves the claim that the Ideas and Principles of Reason are to be used “regulatively,” as devices for guiding and grounding our empirical investigations and the project of knowledge acquisition.

What the Ideas Do Not do, according to Kant,
is provide the concepts through which we might access objects that could be known through the speculative use of Reason.

The need for this critical reinterpretation stems from the fact that Reason’s demand for the Unconditioned cannot be met or satisfied.
The absolutely “Unconditioned,” regardless of the fact that it presents to Reason as objective, is not an object or state of affairs that could be captured in any possible human experience.
In emphasizing this last point, Kant identifies Metaphysics [drives, urge, propensity, proclivity] with an effort to acquire knowledge of “objects” conceived, but in no wise given (or giveable) to us in experience.
In its [Reason’s] efforts to bring knowledge to completion, that is, Reason posits certain Ideas [Pure Concepts of Reason], the “Soul,” the “World” and “God.”
Each of these Ideas represents Reason’s efforts to think the Unconditioned in relation to various sets of objects that are experienced by us as conditioned.

It is this general theory of Reason, as a capacity to think (by means of “Ideas”) beyond all standards of Sense,
and as carrying with it a unique and unavoidable demand for the Unconditioned,
that frames the Kantian Rejection of Metaphysics.

At the heart of that rejection is the view that
although Reason is unavoidably motivated to seek the Unconditioned,
its theoretical efforts to achieve it are inevitably sterile.

The Ideas which might secure such Unconditioned knowledge lack Objective Reality (refer to no object),
and our misguided efforts to acquire ultimate metaphysical knowledge are led astray by the illusion which, according to Kant, “unceasingly mocks and torments us” (A339/B397).

The Dialectic [illusion] is concerned to undermine three distinct branches of special Metaphysics in the philosophical tradition:
1. Rational Psychology, -the Soul
2. Rational Cosmology, the World and
3. Rational theology, God.

Each of these disciplines seeks to acquire knowledge of a particular metaphysical “object” — the “Soul,” the “World,” and “God,” respectively.

This being stated, the Dialectic proceeds systematically to undermine the arguments specific to each of these disciplines—arguments about, for example, the nature of the Soul and the World, and the Existence of God.

Despite the difference in their objects, however, there are a number of problems shared by all the disciplines of special Metaphysics.

In its most general terms, the central problem with each of these attempts has to do with the fact that the alleged “objects” under consideration are “Transcendent.” [attempting to pass beyond limits of experience]

Nb: Kant distinguishes between the Transcendent and the Transcendental.
Transcendent is the term used to describe those Principles which 'profess to pass beyond' the Limits of Experience,
Transcendental signifies those a priori elements which underlie Experience as its Necessary Conditions. Transcendental: all knowledge which is occupied not so much with Objects as with the Mode of our knowledge of Objects in so far as this Mode of Knowledge is to be Possible a priori' (CPR A12).

Although we think the Soul, the World, and God (necessarily) as objects, these Ideas actually lack objective reality (there is no object corresponding to the Ideas that is or could be given to us in any intuition).
It is thus not uncommon to find Kant referring to these alleged metaphysical entities as “mere thought entities,” “fictions of the brain,” or “pseudo-objects.” [illusions]

Although the Dialectic does not presume to prove that such objects do not or could not exist,
Kant is committed by the strictures of his own Transcendental epistemology to
the claim that the Ideas of Reason do not provide us with concepts of “knowable” objects.
For this reason alone, the efforts of the metaphysicians are presumptuous, and at the very least, an epistemological modesty precludes the knowledge that is sought.

Notes:
The point her is while the noumenon or thing-in-itself is illusory, its regulative facilitates the progress of science and morality.

6. Reason and the Appendix to the Transcendental Dialectic
https://plato.stanford.edu/entries/kant ... aAppTraDia
The criticisms of the metaphysical arguments offered in the Transcendental Dialectic do not bring Kant’s discussion to a close.
Indeed, in an “Appendix” to the Transcendental Dialectic, Kant returns to the issue of Reason’s positive or necessary role.
The curious “Appendix” has provoked a great deal of confusion, and not without reason.
After all, the entire thrust of the Dialectic seemed to be directed at “critiquing” and curbing Pure Reason, and undermining its pretense to any real use.
Nevertheless, Kant goes on to suggest that the very reason that led us into metaphysical error is also the source of certain necessary Ideas and principles, and moreover, that these rational postulations play an essential role in scientific theorizing (A645/B673; A671/B699).
Exactly what role they are supposed to play in this regard is less clear.

The Appendix to the Transcendental Dialectic is divided into two parts.
1. “On the Regulative Use of the Ideas of Pure Reason,”
2. (“On the Final Aim of the Natural Dialectic of Human Reason” (A669/B697)

In the first, “On the Regulative Use of the Ideas of Pure Reason,” Kant attempts to identify some proper “immanent” use for Reason.
In its most general terms, Kant is here concerned to establish a necessary role for Reason’s Principle of Systematic Unity.
This Principle of Systematic Unity was first formulated by Kant in the Introduction to the Transcendental Dialectic in two forms,
1. one prescriptive, and
2. the other in what sounded to be a metaphysical claim.

In the first, prescriptive form, the principle enjoins us to
“Find for the conditioned knowledge given through the Understanding
the Unconditioned whereby its unity is brought to completion.”

The complementary metaphysical principle assures us that the “Unconditioned” is indeed given and there to be found.

Taken together, these principles express Reason’s interests in securing Systematic Unity of knowledge and bringing such knowledge to completion.

Kant is quite clear that he takes Reason’s demand for Systematicity to play an important role in empirical inquiry.
In connection with this, Kant suggests that the coherent operation of the Understanding somehow requires Reason’s guiding influence, particularly if we are to unify the knowledge given through the real use of the Understanding into scientific theory (cf. A651–52/B679–80).

To order knowledge systematically, for Kant, means to subsume or unify it under fewer and fewer principles in light of the Idea of one “whole of knowledge” so that its parts are exhibited in their necessary connections (cf. 646/B674).

The Idea of the form of a whole of knowledge is thus said to postulate “complete unity in the knowledge obtained by the Understanding, by which this knowledge is to be not a mere contingent aggregate, but a System connected according to necessary laws” (A646/B676).

Having said this, it should be noted that Kant’s position is, in its details, difficult to pin down.
Sometimes Kant suggests merely that we ought to seek Systematic Unity of knowledge, and this merely for own theoretical convenience (A771/B799-A772/B800).
Other times, however, he suggests that we must assume that the nature itself conforms to our demands for Systematic Unity, and this necessarily, if we are to secure even an empirical criterion of truth (cf. A651–53/B679–81).
The precise status of the demand for Systematicity is therefore somewhat controversial.

Regardless of these more subtle textual issues Kant remains committed to the view that Reason’s proper use is always only “Regulative” and never Constitutive.
The distinction between the Regulative and the Constitutive may be viewed as describing two different ways in which the claims of Reason may be interpreted.

A principle of Reason is Constitutive, according to Kant, when it is taken to supply a concept of a real object (A306/B363; A648/B676).
Throughout the Dialectic Kant argued against this (Constitutive) interpretation of the Ideas and Principles of Reason, claiming that Reason so far transcends possible experience that there is nothing in experience that corresponds with its Ideas.

Although Kant denies that Reason is Constitutive he nevertheless, as we have seen, insists that it has an “indispensably necessary” Regulative use.
In accordance with Reason’s demand, the Understanding is guided and led to secure Systematic Unity and completion of knowledge.
In other words, Kant seeks to show that Reason’s demand for Systematic Unity is related to the project of empirical knowledge acquisition.

Indeed, Kant links the demand for Systematicity up with three other principles — those of
1. homogeneity,
2. specification and
3. affinity
— which he thinks express the fundamental presumptions that guide us in theory formation.
The essential point seems to be that the development and expansion of empirical knowledge is always, as it were, “already” guided by the rational interests in securing unity and completion of knowledge.
Without such a guiding agenda,
and without the assumption that nature conforms to our rational demands for securing unity and coherence of knowledge,
our scientific pursuits would lack orientation.
Thus, the claim that Reason’s principles play a necessary “Regulative” role in science reflects Kant’s critical reinterpretation of the traditional rationalist ideal of arriving at complete knowledge.

It is connection with this that Kant argues, in the second part of the Appendix (“On the Final Aim of the Natural Dialectic of Human Reason” (A669/B697)), that the three highest Ideas of Reason (the Soul, the World, and God) have an important theoretical function.

More specifically, in this section Kant turns
from a general discussion of the important (Regulative) use of the Principle of Systematicity,
to a consideration of the three Transcendental Ideas (the Soul, the World, and God) at issue in the Dialectic.

As examples of the unifying and guiding role of Reason’s Ideas, Kant had earlier appealed to
the Ideas of “pure earth” and “pure air” in Chemistry,
or
the Idea of a “fundamental power” in psychological investigations (cf. A650/B678).

His suggestion earlier was that these Ideas are implicit in the practices governing scientific classification, and enjoin us to seek explanatory connections between disparate phenomena.

As such, Reason’s postulations serve to provide an orienting point towards which our explanations strive, and in accordance with which our theories progressively achieve Systematic interconnection and unity.

Similarly, Kant now suggests that each of the three Transcendental Ideas of Reason (the Soul, the World, and God) at issue in the Dialectic serves as an imaginary point (focus imaginarius) towards which our investigations hypothetically converge.

More specifically, he suggests that
the Idea of the Soul serves to guide our empirical investigations in psychology,
the Idea of the World grounds physics, and
the Idea of God grounds the unification of these two branches of natural science [psychology & physics] into one unified Science (cf. A684/B712-A686/B714).

In each of these cases, Kant claims, the Idea allows us to represent (problematically) the Systematic Unity towards which we aspire and which we presuppose in empirical studies.
In accordance with the Idea of God, for example, we
“consider every connection in the World according to principles [Principien] of a Systematic Unity, hence as if they had all arisen from one single all-encompassing Being, as supreme and all-sufficient cause” (A686/B714).

Such a claim, controversial as it is, illuminates Kant’s view that empirical inquiries are one and all undertaken in light of the rational goal of a single unified body of knowledge.

It also points towards the Kantian view, later emphasized in the Transcendental Doctrine of Method, that Reason’s Theoretical and Practical interests ultimately form a higher unity.

Notes:
The full content of the article:
https://plato.stanford.edu/entries/kant-metaphysics/

CONTENT
1. Preliminary Remarks: The Rejection of Ontology (general metaphysics) and the Transcendental Analytic
2. The Rejection of Special Metaphysics and the Transcendental Dialectic
2.1 The Theory of Reason and Transcendental Illusion
2.2 Hypostatization and Subreption
3. The Soul and Rational Psychology
4. The World and Rational Cosmology
4.1 The Mathematical Antinomies
4.2 The Dynamical Antinomies
5. God and Rational Theology
5.1 The Ontological Argument
5.2 The Other Proofs
6. Reason and the Appendix to the Transcendental Dialectic
Bibliography
Relevant Works by Kant (includes German editions and translations):
Selected Secondary Readings on Topics in Kant’s Dialectic
Academic Tools
Other Internet Resources
Related Entries

Notes:
The general definition of Metaphysics is this:
https://en.wikipedia.org/wiki/Metaphysics

Kant's Definition of Metaphysics. is:

In the period immediately prior to Kant the content of Metaphysics had settled into four sections:

the first was general Metaphysics or ontology, which was concerned, in the words of Wolff's Metaphysics, with 'The First Grounds of our Knowledge and of Things in General';

the remaining three were the Objects and sciences of 'special Metaphysics', namely
1. the Soul and Psychology,
2. the World and Cosmology, and
3. God and theology.

Kant closely followed this Schema in CPR, with the
'Transcendental Analytic' critically treating of Ontology, and
the three sections of the 'Transcendental Dialectic' considering the three parts of special Metaphysics.


The preface to the first edition of CPR begins by evoking a 'species of knowledge' which Reason cannot ignore, but which transcends its powers and throws it into a perplexity of darkness and contradiction. This knowledge is Metaphysics, the Hecuba of the sciences, once queen but now scorned.

Kant proposes a Critique of Reason in respect of knowledge 'after which it may strive independently of all Experience' and through which it will become possible to decide on the 'possibility and impossibility of Metaphysics in general, and determine its sources, its extent, and its limits' (CPR A xii).

For Kant Metaphysics is composed of 'a priori Synthetic knowledge' which 'adds to the given Concept something that was not contained in it' and which may extend knowledge beyond the limits of Experience (B18).

Thus the critical propaedeutic to Metaphysics will examine the proper limits of such Judgements in order to establish whether they may be extended to knowledge of such metaphysical Objects as God, the World and the Soul.
Kant will conclude that they cannot, but this does not lead him to abandon Metaphysics, but rather to undertake a redefinition of its purpose and scope.

In the penultimate section of CPR on 'The Architectonic of Pure Reason' Kant describes Metaphysics as the
'criticism of the faculty of Reason in respect of all its Pure a priori knowledge' and the 'systematic connection [of] the whole body (true as well as illusory) of philosophical knowledge arising out of Pure Reason' (A 841/B869).

Notes

Notes:

Generally, if one [not an expert on Kant] were to understand [not necessary agree with] the above, I guarantee one will surely uplift one's philosophical knowledge a few notches from one present status.
Try it?