Critique of Pure Reason

“Reason has insight only into what it itself produces according to its own plan; and that reason must not allow nature by itself to keep it in leading strings, as it were, but reason must–using principles that underlie judgments–proceed according to constant laws and compel nature to answer reason’s own questions.”

Kant expresses an idea at once continuous with the sense of “mastery over nature” indicative of many thinkers of the age of scientific enlightenment and consistent with his own critical project. Reason must construct order out of the raw material of nature. Reason does not merely understand nature. It produces the world in which we live.

“Thus I cannot even assume God, freedom, and immortality [as I must] for the sake of the necessary practical use of my reason, if I do not at the same time deprive speculative reason of its pretensions to transcendental insight...I therefore had to annul knowledge in order to make room for faith.”

The critical project sets limits to the knowledge to which reason can lay claim. Metaphysical items, like God, the soul, and freedom, can be coherently thought, but not cognized since they are not objects of experience. Abridging the power of reason to know things-in-themselves, like God, allows us to morally relate to them in a way that is practically necessary and faith-centered.

“Now the proper problem of pure reason is contained in this question: How are synthetic judgments possible a priori? That metaphysics has thus far remained in such a shaky state of uncertainty and contradictions is attributable to a sole cause: the fact that this problem, and perhaps even the distinction between analytic and synthetic judgments, has not previously occurred to anyone.”

Kant makes the claim that metaphysics must adequately tackle a single question to advance as a science, a question that, prior to Kant, had not properly been clarified. Synthetic a priori judgments are judgments made by reason independent of sensory experience in which a concept is expanded by the addition of some property that is not identical to the concept itself. Metaphysics advances solely by means of this special kind of judgment.

“The presentation of space cannot be one that we take from the relations of outer appearance by means of experience; rather, only through the presentation of space is that outer experience possible in the first place.”

This encapsulates Kant’s radical revision of the nature of space. According to Kant, space is not something constituted by the objects of the outer world but is instead an intuition of the human mind that is necessary for the possibility of objects of outer awareness. In other words, space is a subjective condition of our consciousness, not an attribute of the world as it is independent of us.

“All our intuition is nothing but the presentation of appearance. The things that we intuit are nothing but the presentation of appearance. The things that we intuit are not in themselves what we intuit them as being.”

Nowhere in our experience of the world do we encounter things as they purely are. Instead, our intuitions are of mere appearances. This view is fundamental to the entire Kantian project.

“Thoughts without content are empty; intuitions without concepts are blind.”

The cognition of the mind is constituted by its capacity for sensation and understanding. The former is determined by intuitions and the latter by thoughts. Kant makes it clear that neither capacity is preferable to the other. Instead, they are dependent upon one another for the fullness of perceptual experience.

“To know what question one should reasonably ask is already a great and necessary proof of one’s sagacity and insight.”

Some might think that wisdom consists in providing accurate answers, but if the question is not itself properly posed and investigated, then the answer may be meaningless and misleading. The value of Kant’s critical philosophy is not that it answers all the questions to which reason demands an answer, but rather because it answers what questions are the right questions to ask in the first place.

“Any necessity is always based on a transcendental condition. There must therefore, be a transcendental basis to be found: a transcendental basis of the unity of consciousness in the synthesis of the manifold of all our intuitions; and hence a transcendental basis also of the concepts of objects as such, and consequently also of all objects of experience–a transcendental basis without which it would be impossible to think any object for our intuitions.”

Kant is simultaneously making two extremely important claims regarding the need for, and success of, his project of transcendental idealism. First, if we hope to establish anything as necessary, universal, and objective, then we must provide a transcendental explanation. Secondly, the specific transcendental basis for the possibility of conscious experience is, most fundamentally, the unity of consciousness, the identity of the self. This is Kant’s revolutionary contribution to the philosophical problem of personal identity.

“The I think must be capable of accompanying all my presentations.”

Kant famously derives the notion of the self, the pure I, during the difficult section on the pure concepts of the understanding. The “I think” reflects an active power of the mind that unites all possible experiences of consciousness. The fundamental claim is that there is a transcendental self-grounding all experience. In part, this is a response to the problematic idealism of Descartes and the skepticism of Hume.

“This schematism of our understanding, i.e., its schematism regarding appearances and their mere form, is a secret art residing in the depths of the human soul, an art whose true stratagems we shall hardly ever divine from nature and lay bare before ourselves. Only this much can we say: The image is a product of the productive imagination’s empirical ability.”

Although the schematism applied from the understanding through the imagination to objects of perception is of fundamental importance, Kant humbly states that its mechanism is largely hidden from his view. There are some arts of the human soul that may forever remain too deeply hidden for the reflective eye to see.

“By nature (in the empirical meaning of the term) we mean the coherence of appearances as regards their existence according to necessary rules, i.e., according to laws. There are, then, certain laws–which are, moreover, a priori–that make nature possible in the first place. Empirical laws can occur and can be found only by means of experience; and this, moreover, in consequence of those original laws through which experience itself becomes possible in the first place.”

What we generally refer to as laws of nature are empirically derived constructions found through experiential engagement with the world. Beneath these “laws” are more fundamental laws through which the experience of nature is even possible. These are synthetic principles of understanding, and they are more certain than the supposedly indubitable scientific laws of nature.

“For if we were to grant this for synthetic propositions, no matter how evident they may be, viz., that without providing a deduction one may on the strength of their own pronouncement commit them to unconditioned approval, then all critique of understanding is lost. And since there is no lack of audacious claims that, moreover, common belief (while being no credential) does not reject, our understanding will then be open to every delusion; it will be unable to refuse its approval to those pronouncements that demand admission, although illegitimately, in the same tone of confidence as do actual axioms.”

Kant takes a hard line on the necessity of providing proof for the synthetic propositions of a system of philosophy. Without this requirement for deductive evidence the ability to critically inquire into the basis of metaphysics is lost and there is no shelter from any ridiculous claim. Axioms must be proven, and if not, assent should not be given to their content.

“It is the land of truth (a charming name), and is surrounded by a vast and stormy ocean, where illusion properly resides and many fog banks and much fast-melting ice feign new-found lands. This sea incessantly deludes the seafarer with empty hopes as he roves through his discoveries, and thus entangles him in adventures that he can never relinquish, nor ever bring to an end.”

The “land of truth” is that of pure understanding, the faculty whose fundamental principles Kant systematically presents. This land is an island, though. Reason, the faculty of the mind that makes inferences, is a stormy ocean, and a difficult one to navigate. Kant is hopeful that with a thorough comprehension of the geography of the understanding we will better be able to traverse the harrowing waters of Reason.

“If the complaints that we have no insight whatever into the intrinsic character of things are to mean the same as that we do not by pure understanding comprehend what the things appearing to us may be in themselves, then these complaints are quite improper and unreasonable. For they then want us to be able to cognize things, and hence intuit them, even without senses, and consequently want us to have a cognitive power wholly different from the human one not merely in degree but even in its intuition and kind; and hence they want us not to be human, but to be beings about whom we cannot even state whether they are so much as possible.”

Kant challenges detractors of his split between the phenomenal and noumenal realms by stating that they complain that he does not offer superhuman insight. For Kant, all knowledge can be only of appearances, but this does not mean that a serious investigation of nature does not lead to a greater understanding of the world. We don’t need to know about the world to discover how it appears to us.

“All our cognition starts from the senses, proceeds from there to understanding and ends with reason, beyond which there is found in us nothing higher to work on the material of intuition and bring it under the highest unity of thought.”

Kant explains the process of cognition as it progresses to higher stages of which reason is the final stage. Reason, while being the highest faculty of the human mind, is also tricky business, and requires a thorough investigation of the dialectic illusions presented therein. All cognition still begins with intuition.

“This refusal of reason to give a satisfying answer to our inquisitive questions reaching beyond this life should be regarded as a hint of reason to turn our self-cognition away from fruitless transcendent speculation and to fruitful practical use.”

The true vocation of reason, for Kant, is in its practical deployment in life for the advancement of human beings. Since the paralogisms reveal that reason is prone to self-delusion in its transcendent principles, it should take the hint that it’s barking up the wrong tree. Instead, reason should focus on its practical usage in empirical reality.

“For his natural predispositions–not merely concerning his talents and the impulses to make use of these, but concerning, above all, the moral law in him–go far beyond all the benefits and advantages that he could draw from them in this life. They go so far beyond these that this moral law teaches him to esteem above everything even the mere consciousness of a righteous attitude–and this in the absence of all advantages, including even the shadowy construct of posthumous fame; and that he feels inwardly called upon to make himself fit, by his conduct in this world and while forgoing many advantages, to be a citizen of a better world, which he has in his idea.”

Despite all our flaws, Kant sees a predisposition in human beings toward the moral law and the realization of a better world, a concern for its fruition even when it goes against our advantage. Because of this, Kant believes that human beings are a purpose unto themselves.

“Yet because of reason’s honor and ever security, neither withdrawing from the quarrel nor watching it indifferently as a mere mock combat is feasible, and even less feasible is simply commanding peace; for the object of the dispute is of great interest. Thus nothing is left for reason but to reflect on the origin of this disunity with itself, in order to see whether the disunity is not perhaps to be blamed on a mere misunderstanding.”

This passage comes during Kant’s reflections on the antinomies of reason. In good faith, reason cannot take up arms on either side of the dispute (between the thesis and antithesis), but it also cannot remain a mere spectator. Reason must, then, find another way to approach these fundamental issues. It does so through its practical application when its speculative application fails, like it does in the antinomies.

“Hence all effort and labor is lost if expended on the famous ontological (Cartesian) proof of the existence of a supreme being from mere concepts; and I suppose, a human being could not from mere ideas become richer in insights any more than a merchant could become richer in assets if he tried to improve his situation by adding a few zeros to his cash balance.”

Kant invokes this analogy to a self-deluded merchant to elucidate the inanity of the ontological argument for the existence of God. In short, God’s existence cannot be proved merely from the concept of a most perfect being.

“Unconditioned necessity, which we so indispensably require as the ultimate support of all things, is for human reason the true abyss.”

This succinctly captures one of the ultimate problems of pure reason. At the base of all logical reasoning, there must be something that is unconditionally necessary for all preceding inferences and premises to have truth value. This unconditional beginning, though, is itself unfathomable. Thus there is an unsurpassable abyss underneath all human reason.

“But this unity of reason among the powers is merely hypothetical. For we are not asserting that such a power must in fact be there. Rather, we are asserting that we must–for reason’s benefit, viz., in order to set up certain principles–seek this absolute basic power for the various rules that may be provided to us by experience, and that we must in this way bring systematic unity into cognition wherever this can be done.”

Kant believes that it is philosophically necessary to bring “systematic unity” to the operations of the faculty of reason. We must do this to establish basic principles and to understand how they are integrated with one another. Although this is an important task, it cannot be assumed that the unity of reason actually exists since we cannot know this. We must simply act as if it does.

“But where the limits of the cognition possible for us are very narrow and the inducement to judge is great, where the illusion offering itself to us is very deceptive and the detriment arising from error is considerable, there an instruction’s negative character, which serves merely to safeguard us from errors, is even more important than is much positive information by which our cognition could be increased. The constraint whereby the constant propensity to deviate from certain rules is limited and finally eradicated is called discipline.” 

There are two distinct but closely related points. First, Kant’s position is that self-imposed restraint in the faculty of reason and the power of judgment are vitally important and can be even more important than actual knowledge of things—if this restraint saves the mind from hubris and terrible error. Second, Kant calls this restraint a discipline, which would seem to indicate strict ongoing practice of willful constraint.

“Yet this predisposition to simulate being better than one is and to express attitudes that one does not have serves only provisionally, as it were, to bring a human being out of the state of crudeness, and to allow him at first to adopt at least the manner of the good familiar to him. For afterwards, once the genuine principles have been developed and have passed over into the person’s way of thinking, that falseness must little by little be combated vigorously; for otherwise it corrupts the heart and keeps good attitudes from springing up under the rank weed of the beautiful semblance.” 

In this section Kant discusses an aspect of proper moral development. At one point (perhaps a young age) a person must overcome his/her nature “crudeness,” or tendency to selfish animal behavior by imitating the good of others with which he/she is familiar. Although this is originally useful, a person must outgrow this inauthentic imitation and flower into an original, autonomous, and moral human being.