Kant

The Way of Critical Philosophy

Kant’s “critical philosophy” consists of an analysis of the powers of human reason, by which he meant “a critical inquiry into the faculty of reason with reference to all the knowledge which it may strive to attain independently of all experience.” The way of critical philosophy is, therefore, to ask the question “what and how much can understanding and reason know, apart from all experience?” Thus, whereas earlier metaphysicians engaged in disputes about the nature of the supreme being and other subjects that took them beyond the realm of immediate experience, Kant asks the critical question whether the human reason possesses the powers to undertake such inquiries. From this critical point of view Kant thought it foolish for metaphysicians to engage in attempts to construct systems of knowledge even before they had inquired into whether by pure reason alone one can apprehend what is not given to him in experience. Critical philosophy for Kant was therefore not the negation of metaphysics but rather a preparation for it. If metaphysics has to do with knowledge that is developed by reason alone, that is, prior to experience, or a priori, the critical question is how is such a priori knowledge possible.

The Structure of Rational Thought

Kant says that “there are two sources of human knowledge, which perhaps spring from a common but to us unknown root, namely sensibility and understanding. Though the former objects are given to us; through the latter they are thought.” Knowledge is, therefore, a cooperative affair between the knower and the known. But although I am able to distinguish the difference between myself as a knower and the thing I know, I can never know that thing as it is in itself. For the moment I know it, I know it as my structured mind permits me to know it. If colored glasses were permanently fixed to my eyes, I should always see things in that color and could never escape the limitations placed on my vision by those glasses. Similarly my mind always brings certain ways of thinking to things, and this always effects my understanding of them. What does the mind bring to the given raw materials of experience?

 The Categories of Thought and the Forms of Intuition

 The distinctive activity of the mind is to synthesize and to unify our experience. It achieves this synthesis first by imposing on our various experiences in the “sensible manifold” certain forms of intuition: space and time. We inevitably perceive things as being in space and time. But space and time are not ideas derived from the things we experience, nor are they concepts. Space and time are encountered immediately in intuition and are, at the same time, a priori or, to speak figuratively, lenses through which we always see objects of experience.

In addition to space and time, which deal particularly with the way we sense things, there are certain categories of thought which deal more specifically with the way the mind unifies or synthesizes our experience. The mind achieves this unifying act by making various kinds of judgments as we engage in the act of interpreting the world of sense. The manifold of experience is judged by us through certain fixed forms or concepts, such as quantity, quality, relation and modality. When we assert quantity we have in mind one or many; when we make a judgment of quality, we make either a positive or negative statement; when we make a judgment of relation, we think of cause and effect, on the one hand, or of the relation of subject and predicate on the other; and when we make a judgment of modality, we have in mind that something is either possible or impossible. All these ways of thinking are what constitute the act of synthesis through which the mind strives to make a consistent single world out of the manifold of sense impressions.

Phenomenal and Noumenal Reality

A major impact of Kant’s critical philosophy was his insistence that human knowledge is forever limited in its scope. This limitation takes two forms. In the first place, knowledge is limited to the world of experience. Second, our knowledge is limited by the manner in which our faculties of perception and thinking organize the raw data of experience. Kant did not doubt that the world as it appears to us is not the ultimate reality. He distinguished between phenomenal reality, or the world as we experience it, and noumenal reality, which is purely intelligible, or non-sensual, reality. When we experience a thing, we inevitably perceive it through the “lenses” of our a priori categories of thought. But what is a thing like when it is not being perceived? What is a thing-in-itself (Ding an sich)? We can obviously never have an experience of a non-sensuous perception. All objects we know are sense objects. Still, we know that the existence of our world of experience is not produced by the mind. The mind, rather, imposes its ideas upon the manifold of experience, which is derived from the world of things-in-themselves. This means that there is a reality external to us that exists independently of us but that we can know only as it appears to us and is organized by us. The concept of a thing-in-itself does not, then, increase our knowledge but reminds us of the limits of knowledge.

Transcendental Ideas of Pure Reason as Regulative Concepts

Besides the general concept of the noumenal realm, there are three regulative ideas that we tend to think about, ideas that lead us beyond sense experiences but about which we cannot be indifferent because of our inevitable tendency to try to unify all our experience. These are the ideas of the self, of the cosmos, and of God. They are transcendental because they correspond to no objects in our experience. They are produced not by intuition but by pure reason alone. They are, however, prompted by experience in the sense that we think those ideas in our attempts to achieve a coherent synthesis of all our experience. Kant says that “the first (regulative) idea is the ‘I’ itself, viewed simply as thinking nature or soul … endeavoring to represent all determinations as existing in a single subject, all powers, so far as possible, as derived from a single fundamental power, all change as belonging to the states of one and the same permanent being, and all appearances in space as completely different from the actions of thought.” In this way our pure reason tries to synthesize the various psychological activities we are aware of into a unity, and it does this by formulating the concept of the self.

Similarly, pure reason tries to create a synthesis of the many events in experience by forming the concept of the world so that “the second regulative idea of merely speculative reason is the concept of the world in general … The absolute totality of a series of conditions … an idea which can never be completely realized in the empirical employment of reason, but which yet serves as a rule that prescribes how we ought to proceed in dealing with such series … The cosmological ideas are nothing but simply regulative principles, and are very far from positing … and actual totality of such series.” Kant continues, “the third idea of pure reason, which contains a merely relative supposition of a being that is the sole and sufficient cause of all cosmological series, is the idea of God. We have not the slightest ground to assume in an absolute manner the object of this idea … It becomes evident that the idea of such a being, like all speculative ideas, seems only to formulate the command of reason, that all connection in the world be viewed in accordance with the principles of a systematic unity … as if all such connection had its source in one single all-embracing being as the supreme and sufficient cause.”

Kant’s use of these regulative ideas exemplify his way of mediating between dogmatic rationalism and skeptical empiricism. With the empiricists, Kant agrees that we can have no knowledge of reality beyond experience. The ideas of the self, the cosmos, and God cannot give us any theoretical knowledge of realities corresponding to these ideas. The functions of these ideas is simply and solely regulative. As regulative ideas, they give us a reasonable way of dealing with the constantly reoccurring questions raised by metaphysics. To this extent Kant acknowledged the validity of the subject matter of rationalism. His critical analysis of the scope of human reason, however, lead him to discover that earlier rationalists had made the error of treating transcendental ideas as though they were ideas about transcendent or actual beings. Kant emphasizes that “there is a great difference between something given to my reason as an object absolutely, or merely as an object in the idea. In the former case our concepts are employed to determine the object (transcendent); in the latter case there is in fact only a schema for which no object, not even a hypothetical one, is directly given, and which only enables us to represent to ourselves other objects in an indirect manner, namely in their systematic unity, by means of their relation to this idea. Thus, I say, that the concept of a highest intelligence is a mere idea (transcendental).”