KANT’S CRITICAL EPISTEMOLOGY AND ITS BORDERLINES WITH METAPHYSICS: A CRITIQUE

This paper focuses extensively on Kant’s critical epistemology as postulated in his Critique of Pure Reason. It grapples with the problem of identifying and harmonizing these borderlines of empirical and rational knowledge with that of metaphysical knowledge. Kant argues that the mind is so structured and empowered that it imposes interpretative categories on our experience so that we do not simply experience the world, as the empiricists claim, but interpret it through the categorizing mechanism of the mind. In ruling out indifference to metaphysical questions, Kant posits that if metaphysics is not science, yet still as natural disposition, human reason is driven on ‘by an inward need’ and not by mere ‘idle desire’ to ask metaphysical questions. Furthermore, Kant posits that what makes skepticism about metaphysics unsustainable is that metaphysics cannot be discarded in isolation from cognition in general. Kant, therefore, is of the view that the very same principles of reasoning as are employed in empirical judgments about physical objects are also used in a purified form, in metaphysical judgments about God, the soul and other non-empirical entities. However, the paper criticizes Kant for being too anxious to prove the subjectivity of space, as an escape route from materialism. Kant was quite averse to the argument that if space is objective and universal, God must exist in space, and hence, be spacial and material in nature. Thus, Kant might have been satisfied with the critical idealism which holds that all reality is known to us as our sensations and ideas.


INTRODUCTION
A number of antecedent factors helped shape Kant's critical philosophy. His philosophical development was characterized by constant and unforeseeable vacillation. Kant's original philosophical orientation may be described as rationalist, but his 'precritical' works, put together, do not express a unified philosophical outlook. His approach appears to be that of continual dissatisfaction and experimentation.
The intellectual revolution Kant brought into modern philosophy was actually shaped by some philosophical problems of his day that required further investigation. Voltaire, Francis Bacon and the continental rationalists have elevated reason with their unquestioning confidence in the power of science and logic to solve human problems. This historical epoch witnessed the apotheosis of the intellect and the worship of the "goddess of reason" (Durant 1961:211).
However, beyond the euphoria that greeted the rise of rationalism lies its inadequacies to produce the kind of knowledge Newtonian physics represented. Newton's scientific thought limits knowledge to the domain of sense experience and to general conclusions from such experience based on inductive reasoning. On the other hand, the metaphysical speculations of the rationalists about reality beyond sense experience could not yield much results as science did, hence were considered dogmatic by Kant. The work of the British empiricist, David Hume, Treatise on Human Nature (1748) also had a profound influence on Kant (Hume 1999:1). He wrote that it was Hume that roused him from the "dogmatic slumber" in which he had assumed without question the essentials of religion and the bases of science. Hume's hard core empiricism negates the notion of causality and inductive inference upon which science is erected. Following the arguments of Hume to a logical conclusion would lead one to accept that scientific employ in the course of experience and which this experience at same time abundantly justifies it in using'. Viewed critically, Kant's position seems to rest on a sound logic. If one and the same reasoning faculty is employed in empirical and metaphysical investigations or judgments and the empirical employment of reason is considered legitimate the same should also be the case in its metaphysical employment. If, however, metaphysics results in contradictions, then reason as a whole contradicts itself. So then, to allow the contradictions of metaphysics to stand is to allow reason to perform a reductio ad absurdum upon itself. Hence, to abandon metaphysics is to abandon cognition as a rational phenomenon. In this circumstance, the problem that metaphysics presents must be addressed in some other ways then by its repudiation (Gardner 1999:20, 21).
The possibility of metaphysics, for Kant, unlike Hume, is not open to doubt. The question is not whether metaphysics is possible but how metaphysics is possible. Since the question borders on legitimacy rather than of fact, it cannot be answered empirically. On the other hand, since the question concerns the possibility of metaphysics, its answer cannot itself consist in a metaphysical claim or stand upon any metaphysical presuppositions. In as much as the problem of metaphysics is ultimately a matter of reason's relation to itself, the route to its solution, Kant maintained, must also be reflexive (reason must examine itself). To accomplish this, implies that we must make reason itself an object of philosophical investigation instead of seeking knowledge of transcendent reality. In view of this, Kant demands reason 'to undertake anew the most difficult of all its tasks, namely, that of selfknowledge, and to institute a tribunal which will assure to reason its lawful claims'. As Gardner puts it "this tribunal intended to replace the irrationality of a battle field with the rationality of a court of law, is 'no other than the "Critique of Pure Reason"

The Critique Of Pure Reason
What Kant meant by critique is not mere criticism of "pure reason" or a negative evaluation of its object but rather a critical analysis or enquiry; the results of which may equally be positive. Hence, his objective is not to attack "pure reason" except at the end, to show its deficiencies or limitations but rather to show its possibility, and to raise it above the impure knowledge which comes to us through the transient and distorting channels of sense. The word 'pure' used in a technical way, means independent from, free from or not containing anything derived from sense experience. 'Reason' is also used by Kant here in a technical sense to refer to conceptual elements in cognition which we bring to experience and which are not derived from it -in Kant's language, 'a priori conceptual elements. In all, a critique of pure reason is a critical analysis or enquiry into the capacity of the mind to know anything by employing our reason independently or in isolation of the senses (without conjoining reason with sense experience). More specifically, the critique enquires into the capacity of the mind to know things lying beyond the bounds of sense experience, such as God, the soul and other non-empirical entities (Gardner 1999:23). Such knowledge is deemed to be pure having come to us by the inherent nature and structure of the mind.

Kant's Critical Epistemology
Kant's copernicanism or "the Copernican revolution" introduced significant changes in the way we, hitherto, perceive things in philosophy. The transformation in the concept of an object that comes with this revolution revises the relation between metaphysics (or ontology) and epistemology, and in a sense obscures the boundary between them. In the pre-Copernican philosophy there is a clear conceptual distinction between the questions of what is the constitution of reality? (the metaphysical question) and how do we attain knowledge of reality? (the epistemological question). Although these two lines of inquiry are bound to be intertwined in any notable philosophical system, they are however, separable in principle, as a result of the detachability of knowability from objecthood to which pre-Copernican philosophy is committed (Gardner 1999:39). The traditional metaphysical/ontological question is suspended by Kant. For him, fully real things are not objects that we can intelligibly seek knowledge of, -and this implies that the sense of the epistemological question has been revised accordingly. The transcendental question concerning the conditions under which objects are possible for us is, therefore, not equivalent to a question about the condition of being, or to a question about the condition under which objects can be known, and cannot be resolved back into either of them (or their combination) as the case may be.
The Copernican revolution in philosophy is often associated with an 'epistemological turn' in philosophy . This means that it considers all metaphysical questions from an epistemological, justificatory angle. As Kant puts it, it replaces 'the question of fact (quid facti)' with 'the question of right (quid juris)'. The problem with this approach is that it fails to capture the sense in which it is also intended to change the very framework within which epistemological questions are understood. Moreover, it blurs the important point that, even if epistemology could demonstrate that our cognitive relation to objects is immune to all of the familiar forms of skepticism, it would still not supply what is most fundamentally needed philosophically. This is simply because it would still not have dealt with the question of what makes it possible for a real thing to become an object for us (Mitchell 2011:255).
Kant is of the view that pre-critical epistemologies are excluded from providing the kind of doubt-proof justification for knowledge claims to which Descartes earlier hoped to achieve. The intention for transcendental philosophy lies in a demand for philosophical explanation which is detached from the Cartesian quest for indubitable knowledge. At this juncture, it is quite germane to note that the term transcendental as used by Kant, has nothing to do with what (or if anything) lies beyond experience (Gould & Mulvaney 2007:272).
In the Kantian context, the term transcendental refers to the a priori conditions mind imposes on things for their occurrence within experience (Lamprecht 1955:365). Suffice it to say that the epistemological turn in Kant's critical philosophy is only one aspect of his far-reaching 'transcendental turn' (Gardner 1999:40).

On The Nature Of A Priori Knowledge
Kant, at the very outset of the Critique challenged the position of the British Empiricists by positing that all knowledge is not derived from sense experience (Kant 1781:1). Hume, specifically, attempted at showing that there is no soul, and no science. He argued that our minds are but our ideas in procession and association, and our certainties nothing but probabilities in perpetual danger of violation (Durant 1961:201.). For Kant, these are false conclusion resulting from false premises. He argued that we cannot assume that all knowledge comes from "separate and distinct" sensations. In natural terms, these cannot give us necessity, or invariable sequences of which we may be perpetually certain. Besides, it is naturally impossible to see a metaphysical entity like the soul even with the eyes of internal sense. One may grant that absolute certainty of knowledge is impossible if all knowledge originates from sense, from an independent external world which owes us no promise of consistency. Again, Kant asked what if we have knowledge whose truth is certain to us even before sensing experience -a prior? Then, this would make absolute truth, and absolute science possible. The question here is: "is there such absolute knowledge?", "What can we hope to achieve with reason when all the material and assistance are taken away". The Critique could be described as a detailed biology of thought, an examination of the origin and evolution of concepts, an analysis of the inherited structure of the mind. This issue, as Kant posited, constitutes the whole problem of metaphysics (Durant 1961:202). In his words, "In this book I have chiefly aimed at completeness; and I venture to maintain that there ought not to be one single metaphysical problem that has not been solved here, or to the solution of which the key at least has not been supplied" (Pref. xxiii).
Kant believed that "Experience is by no means the only field to which our understanding can be confined. Experience tells us what is, but not that it must be necessarily what it is and not otherwise (1). He concluded that experience never gives us any really general truths. Our reason, which is particularly anxious for that class of knowledge is awakened by it rather than satisfied. He opined that "General truths, which at the same time bear the character of an inward necessity, must be independent of experienceclear and certain in themselves" (1). That is to say that general truths must be what it is irrespective of what our later sensory experience may suggest. It must be true even prior to experiencethat is, true a priori. Using the example of mathematical knowledge, Kant argued that there are truths we can advance independently of all experience. Mathematical knowledge is deemed necessary and certain, hence, we cannot think of any future experience that could vitiate such truths as 2+2 = 4, 2x2 = 4 are true before real experience and as such do not rely on any past, present of future experience. We can, therefore, hold such to be absolute and necessary truths in mathematical context, just as the Cartesian epistemology attempted to build indubitable knowledge on such mathematical principles. Experience, on the other hand, gives us nothing but separate sensations and events which may change their sequence in future. We may conclude, therefore, that these absolute truths derive their necessary character from pure reason, from the mind which frames and organizes sensations into ideas and transforms the chaotic multiplicity of experience into well-ordered unity of thought (Durant 1961:202).

Varieties Of Judgment
In the introduction to the Critique of Pure Reason, Kant asked "How are synthetic a priori judgments possible? He claimed to have discovered a new distinction between kinds of judgment, as well as a new class of judgments which neither rationalism nor empiricism can account for. The distinction in question is between what Kant refers to as 'analytic' and 'synthetic judgments. In respect of the judgments which are problematic for rationalism and empiricism, he called such 'synthetic a priori' judgment. Kant sought to find an answer to the question of how are synthetic a priori judgments is possible? He attached great importance to this question that he blamed the problem of metaphysics on the fact that this question has never previously been considered. In view of this, Kant, attempted a logical formulation and clarification of the problem of metaphysics and even advance the case for its possibility.

Analytic And Synthetic Judgments
A judgment, as Kant put it, is an operation of thought whereby we connect a subject and predicate, where the predicate qualifies in some way the subject, for example, "The building is tall" (Stumpf 2003:286). Some of our judgments are analytical and some are synthetic.
A judgment is analytic if the predicate is "(covertly) contained in" and 'thought in' the concept of the subject. In other words, analytic judgments are those in which the predicate term either repeats the subject term or divides the subject term into elements, so as to make clear some one of the various elements which was already obscurely intended by it (Lamprecht 1955:362). An analytic judgment merely displays a constituent of the concept of the subject and is true by virtue of the principle of contradiction. An example of an analytic judgment is "All bodies are extended," for the idea of extension is built into the idea of bodies. In the same vein, the judgment 'a triangle has three sides' is analytic because the concept of three-sidedness is contained in that of triangularity and its negation is contradictory (Gardner 1999:54). Thus analytic judgments are true because of the logical relation of subject and predicate (Stumpf 286).
Synthetic judgments, on the other hand, are those judgments in which the predicate term adds something that was not either explicitly or implicitly contained in the subject term. This is to say that a judgment is synthetic if the predicate that it connects with the concept of the subject is not contained or 'thought' in it. The connection of subject and predicate is 'thought without identity', and the judgment must be true by virtue of something other than the principle of contradiction. This kind of judgment rests on a 'synthesis' or the addition of something quite new to our concept of the subject, a brining into connection of elements not previously put together. An example of synthetic judgment is "All bodies are heavy [have weight]' for the concept of weight is not contained in that of the body and is added to it through experience. The form of all synthetic judgments, is therefore, 'that which satisfies concept A (where A=B+C) satisfies concept D" (Gardner 54). This suggests that synthetic judgments add to the content of cognition and extend our knowledge, as analytic judgments cannot do.
Kant also made a distinction between a priori judgments (that is, based on reason) and judgments that are a posteriori (that is, based on experience) respectively. In this regard, all analytic judgments are considered as a priori since their meaning does not rely on our experience of any particular cases or events. A priori judgments are totally independent of experience or any observations as in mathematical knowledge. In contrast synthetic judgments are largely based on experience or empirical observation. For example, "All dogs in the city have long tails". For this reason, Kant concludes that most synthetic judgments are a posteriori (Kant's preferred term is 'empirical' rather than a posteriori).

Synthetic A Priori Knowledge
Kant went beyond the old distinction between necessary and a priori, and contingent and empirical knowledge. From the standpoint of Leibniz and Hume, one would expect all necessary and a priori judgments to be analytic and all contingent and empirical judgments to be synthetic. But according to Kant, all contingent and empirical judgments are indeed' synthetic but not all necessary and a priori judgments are analytic. For him metaphysical judgments, whilst being a priori, are nevertheless synthetic. He accepted that some propositions found in metaphysical works, like "God is a perfect being', are merely analytic but maintained that those which really interest us are intended to extend our knowledge, to inform us about something new, and so must be synthetic. To say that 'every event has a cause' is not analytic, for the concept of the predicate is not contained in the concept of the subject. For this reason such judgment is informative, and thus, synthetic in as much as the concept of an event does not contain that of being an effect. Metaphysical judgments, for Kant, is therefore a priori (because they are necessary) and synthetic (because they extend our knowledge). This implies that they cannot be derived from either logic (since they are synthetic) or experience (since they are a priori). Given that this kind of judgment is not wholly analytic (a priori) and synthetic (a posteriori), Kant called it synthetic a priori. But the question is, 'how is synthetic a priori judgment possible?' This question arises because by definition synthetic judgments are a posteriori (based on experience) and cannot be a priori (independent of experience). Again, if judgment is a priori how is it possible for it to extend our knowledge? This is because any extension of knowledge would seem to require experience. Kant showed that in metaphysics, ethics, mathematics and geometry, we do make judgments that are partly a priori and synthetic.
Mathematical judgments, he argued, are necessary and a priori (analytic), but at the same time require some kind of synthesis. In contrast with the position of Leibniz that 7+5 = 12, Kant argued that the concept of "the sum of 7 and 5' does not contain the concept of "the number 12". In order to determine which number is it, intuition is required, and this makes the judgment synthetic as well. That is to say that there is need for synthesis to make the connection between the subject, 'sum of 7 and 5' and the predicate to be '12'. Kant's position contradicts Leibniz's view that mathematics can be derived from logical principles.
Kant also assigned the same synthetic a priori status to geometrical judgments. The judgment 'A straight line is the shortest distance between two points' is synthetic because the concept of straightness does not contain any information regarding the relative lengths of different lines joining two points. Just like in mathematics, synthesis is also required, to bridge the gap between 'straight line' and 'shortest distance between two points'. Similarly, Kant showed that the principles of Newtonian physics, like the laws of conservation of mass, and of equality of action and reaction, are synthetic a priori (Gardner 1999:57).
From the foregoing, it is obvious that if mathematics and geometry are to be possible we must disagree with the view of Leibniz and Hume on the sources of knowledge. Kant, therefore, posited that if synthetic a priori judgments could be justified in mathematics and geometry, the same could also be applicable to metaphysics. He demonstrated that metaphysical judgments cannot be rejected for Hume's reasonon the grounds that they do not derive from either logic or experience. Mathematics and geometry which Hume did not doubt, indicate that it is possible and justifiable for us to have knowledge which is necessary but not logically necessary. So then, there is reason for believing that metaphysical knowledge, which lays claim to the same status, may possible as well.

Kant's Transcendental Dialectic
The transcendental dialectic is the last long section of Kant's seminal work, Critique of Pure Reason. In the Kantian sense of the term, a dialectic has to do with an activity of reason in which reason refuses to work within the limits of understanding. In a broader scope, a transcendental dialectic is one in which this refusal is due to efforts to use the forms of sensibility and categories of understanding to determine the nature of objects of which the mind is in no way constitutive (Lamprecht 1955:372).
In the Dialectic, Kant carefully provided a detailed critique of transcendent metaphysics (Bird 2017:1). Whereas, in the Analytic, he argued against the empiricist, conception of experience in support of the rationalist's claim that pure reason is necessary for knowledge, in the dialectic, Kant opposed the rationalist conception of the scope of reason, in support of the empiricists' position that objects must be experienced in order to be known. For the greater part, the philosophy of Leibniz appears to be the target of the dialectic (Leibniz 2003:162).
Kant in the dialectic did show that transcendent ideas are not futile but have importance for natural science. Although morality is excluded from domain of the Critique (but focused on in the Critique of Practical Reason), the dialectic supplies some of the necessary materials for the construction of Kant ethical theory. By virtue of this it provides an essential link between Kant's theoretical and practical philosophy. The transcendent experience in general of things as existing contingently, from which the existence of an absolutely necessary being is inferred. The argument from design, on its part, is grounded on "determinate experience", of the world as having an orderly constitution, which proponents hold on to establish the existence of its creator (Gardner 1999:237). By Kant's standard, all these attempts to prove God's existence by theoretical reason has paralogism. 'Transcendental Dialectic' must remind theology that substance and cause and necessity are infinite categories, modes of arrangement and classification which the mind applies to such experience. It is reliably valid only for the phenomena that appear to such experience. Consequently, we cannot apply these conceptions to the noumenal (or merely inferred and conjectural) world. The fact, therefore, remains that theological matters being metaphysical cannot be proved by pure theoretical reason.

Kant's Distinction Of Noumena And Phenomena
In the Analytic, Kant reaffirmed with some modifications, the traditional distinction of sensory and mental (intellectual) objects in epistemology. This he did by introducing the twin concepts of noumenan (plural, noumena) and phenomenon (plural, phenomena). A noumenon Kant explained, is an object exclusively of understanding an object given to a subject but only to its intellect or understanding. In other words, it has to do with a realm of reality not given by the senses. This concept, however, does not suggest any contradiction, in so far as (the Aesthetic affirmed), we can form the idea of the sense. The noumenal reality, lacking all features of sensibility, is a purely intelligible domain, (the term "intelligible" being Kant's term of contrast for sensible), the constitution of which can be grasped exclusively through the intellect. It follows, therefore, that a subject with a discursive intellect, could know or be aware of a noumenon only if such a subject could engage the categories independently of the senses.
It is quite germane to note at this juncture that the concept of an object (as distinct from a subject) exclusively of understanding has a very close affinity with that of a thing-initself. This is due to the fact that a thing-in-itself is also regarded as a thing that exists independently of the senses. Consequent upon this, noumena, represented (as objects exclusively of understanding) are "represented as they are" not "as they appear" (Kant,, and the concepts of noumenon and a thing-in-itself, it they refer, refer to the same things (306,310). This notwithstanding, the concepts of noumena and a thing-initself are not one and the same thing. The thing-in-itself is a bare ontological concept referring to an object as it is constituted in itself independent of our awareness of knowledge of its existence. In other words a thing-in-itself is a thing considered even apart from the categories, though that is not to say that it is a thing considered as non-categorical -as necessarily, intrinsically non-conformable to the categoriesin the same way that it is nonspatial and non-temporal (Gardner 1999:201). On the other hand, the concept of noumenon is an epistemological concept which stands for an object of certain mode of cognition, namely "intellectual intuition", and totally free from sensibility. As Gardner explained it, "In moving from the concept of the thing-in-itself to that of noumenon, we thus, reconceived transcendent reality as determined for cognitionas individuated and characterized in ways that allow of being known" (201).
By this activity, the concept of noumenon provides an answer to the question of what would be needed for a thing-in-itself to become an object of knowledge. Moreover, the concept epitomizes what Leibniz's epistemology and metaphysics presupposed through this idea of monads.