Critique of Practical Reason by Immanuel Kant

First published:Kritik der praktischen Vernunft, 1788 (English translation, 1873)

Type of work: Philosophy

The Work:

In The Critique of Practical Reason, Immanuel Kant argues that principles are subjective (and therefore maxims) if one person considers them; they are objective (and therefore imperatives) if every rational being considers them. Imperatives are either hypothetical or categorical. A hypothetical imperative demands a course of action to achieve a specified result; for example, “If I want to stay dry in the rain, then I should take my umbrella with me.” A categorical imperative demands a course of action under all possible circumstances; for example, “Thou shalt not commit murder.”

According to Kant, hypothetical imperatives respond to desires, while categorical imperatives constitute rationality. Subjective principles and hypothetical imperatives are empirically oriented; neither can be a fundamental determiner of moral motivation since they serve self-interest. Proper moral motivation cannot follow fleeting pleasures or displeasures; it must follow a noncompromising rationality. Rational beings must imagine their maxims as practical and general laws that fit into a mold of moral rationality. No matter what one plans, the logical form of rationality urges a logical analysis of one’s actions. To test one’s decisions, one uses an imperative, which is immutable. A basic requirement of morality, autonomous motivation, undergirds this immutable law. Any heteronomy entails random authority (Willkür).

Objects inspire pleasure or displeasure; rationality must be free of empirical attractions, having nonsubjective status. Kant provides an example of testing by rationality: Kant is the recipient of a deposit. The owner has died without leaving a financial record for his heirs. However, Kant cannot deny the existence of the deposit even though no evidence of the deposit exists. If everyone who entered into a contract did so planning to deny the existence of that contract, contracts themselves would cease to exist, rendering the act of falsely contracting itself incoherent.

Kant’s example depends upon his formulation of the categorical imperative: “Act such that the maxim of your will can always count also as a principle of general legislation for all.” In other words, it should always be logically possible for the maxim behind one’s action (for example, “I should only keep promises when it is convenient”) to be universalized (for example, “Everyone who finds their promises inconvenient should break them”). The reason this example maxim cannot be generalized is that, if it were, there would no longer be such a thing as a promise. Thus, generalizing the maxim results in logical incoherence, violating the laws of reason.

Kant’s practical rule is unconditional; thus, it is a categorical, practical proposition with an a priori truth-value. Even when one follows subjective desires, one must be able to imagine them as tested by moral law. This law is not a derived one; it urges itself upon the mind as part of the structure of rationality as such. Any search for happiness must include the search for the happiness of all who share in one’s rationality. The moral community that this concept refers to may vary with changing times and views; Kant does not commit to one ethnic group or even one species.

Selfish expansion of one’s happiness makes no sense as a moral ideal. Kant gives the example of an Epicurean reference: If one were to recommend a particular job candidate to maximize the candidate’s own pleasures, wealth, or power, a human-resource specialist would reject the recommendation as either mad, mocking, or backstabbing. Furthermore, if one acts wrongly, one must be able to conceive of a punishment for wrongdoing. However, it would be nonsensical to anticipate punishment—that is, a reduction of well-being—in return for reducing one’s well-being by not sufficiently seeking happiness. Thus, seeking happiness cannot be a moral virtue. Morality is rooted in rationality, not in Epicurean pleasure.

In the Kritik der reinen Vernunft (1781; Critique of Pure Reason, 1838), Kant had shown that time and space are mental conditions of how the mind perceives the world. Beyond these phenomena, one can know of a thing-in-itself but cannot experience it. A similar relationship obtains between humans as natural beings and humans as transcendent rational beings. In the evaluation of its perceptions, the mind can rely on the world of phenomena to corroborate its hypotheses with further observations; however, no corroboration is possible with rationality, and moral law is pure rationality. Causation in moral rationality is a given condition of good will. Like geometric figures, the moral law is purely mental.

For Kant, one must ask whether one’s plans are possible under the conditions of good will. Morality springs directly from this good will (well-functioning motivation); without that directness, the action does not constitute morality. Self-interest is acceptable, as long as the good will has conditioned it; if so, selfishness is unlikely to become arrogance or outright selfish egoism. The moral law is holy for a perfect being, but, for the will of a finite rational being, the moral law inspires duty and awe. Kant asserts that passionate or emotional commitments to faddishly tearful good-works moralities are on the wrong path: Only a clear moral duty guided by good will produces morality.

Respect focuses on persons, never on things. One may like, love, or fear animals, but one does not respect them. However, persons have a sense of equality. Before a person of high rank, one may bow, but one’s spirit never bows. One must have respect for all persons, regardless of social rank. Personhood must be holy to all. Anything can serve as instrument and means, but people are ends in themselves.

“Moral rationality” and “good will” are synonyms for Kant. The highest value, thus, must include the moral law. Epicureans and Stoics obfuscate each other semantically. For the Epicureans, the highest happiness is virtue; for the Stoics, virtue is the highest happiness. Kant resolves the resulting chicken-or-the-egg question (does worldly happiness cause the maxims of virtue or vice versa?): Since only the maxims of virtue are intrinsically rational, only they can be causative. Nothing in the world can produce moral rationality because it exists independently of the world. Thus, individuals experience themselves independently, outside of time. Conditioned by the moral law, this independent motivation is an operative part of rationality. Cultivating this rationality, one achieves self-contentment (Selbstzufriedenheit), a condition similar to happiness.

“Immortal soul” is a required concept in understanding the good will because the will engages in self-improvement endlessly. Only a being that understands itself as eternal could engage in such a process without despairing. A person’s infinite identity must be a metaphor of ethics. One assumes the “soul” as one assumes a “god” metaphor, which provides an image of self-perfecting. Rationality works toward a “god” goal in perfecting itself. A “god” metaphor answers a practical need; one cannot have a duty to believe in an existing “god.” However, there is a duty to conceptualize the highest good, and doing so is easier when it is imagined in relation to a “god” metaphor.

Christian morality is part neither of the moral law nor of the “god” metaphor, according to Kant. Freedom, immortality, and God are not matters of knowledge; they are transcendent ideas held for logical convenience. One assumes “god,” “freedom,” and “immortality” for the convenience of moral rationality, although one can never prove them compellingly in the empirical world. One also cannot compel faith; indeed, one benefits by not knowing God and eternity. If one knew those entities, one might act out of fear or hope rather than duty. To do so, however, would annihilate the moral worth of one’s actions; it would replace the categorical “I must do this because it is my duty” with the hypothetical and self-interested “I must do this in order to avoid God’s wrath and attain His rewards.” Motivation from fear or hope would be immaturely mechanical. One must look to the autonomous judge inside, not to heteronomous forces outside. Obedience to human laws is legality, not morality. Legality commonly results in hypocrisy and in doing what advances one’s interests under a pretense of lawfulness while one looks for loopholes.

To show that practical rationality is universal, Kant tells of a ten-year-old’s reaction to a story about a person who is to bear false witness, such as speaking ill of Ann Boleyn in support of Henry VIII. Bribed by wealth and threatened by pain, loss, and solitude, the person refuses wrong testimony. The ten-year-old clearly recognizes the superior virtue of this person. Further, if one rescues people from a sinking ship and if one loses one’s own life in the process, one has practiced a morality that should not be endorsed fully since that person was negligent in his or her duty to him- or herself. Sacrificing oneself to one’s country is laudable, yet it suffers the same deficiency of not seeing one’s obligations to oneself. Thus, intuition will recognize these moral categories as qualities of behavior universally.

Because morality is a condition of rational beings, such beings follow the good will. Kant sums up lyrically with the following:

Two thoughts fill me with ever renewing and increasing awe: the starry sky above and the moral law within. The starry sky reminds me of the animal self that has visited the planet for a short while but must return its living matter to the planet. The moral law within places me into a world of transcendent infinity. The former diminishes me; the latter exalts me.

Kant’s analysis focuses on how to think morally; it does not explain how to live. His analysis leaves one free to think for oneself. The Critique of Practical Reason is powerful precisely because it does not micromanage morality. Kant describes rationality; he does not proscribe behavior. Morality must focus on a wide moral community and not merely on the self, a mainstay of any ethicist’s thinking.

Taking responsibility for one’s actions is an essential part of ethical thinking. The moral agent within makes all decisions. A moderate measure of expedience can be part of duty ethics. Kant suggests supplications with fingers crossed when one can bow to a person of high rank without bowing with one’s inner self; a lie or some measure of hypocrisy seems implicit. Kant does not offer a proof of God, the soul, or free will; he merely suggests that these are good metaphors for thinking about morality. One cannot compel anyone to believe; a metaphor does not require an existing referent.

Kant’s thinking is foundational in moral theory. No ethicist today can work without an awareness of Kant’s philosophy. At the same time, many thinkers also misunderstand Kant, in part because of his incredibly complicated syntax, which doubtlessly challenges translators.

Bibliography

Beck, Lewis W. A Commentary on Kant’s “Critique of Practical Reason.” Chicago: University of Chicago Press, 1960. A useful explication of Kant’s moral philosophy.

Freydberg, Bernard. Imagination in Kant’s “Critique of Practical Reason.” Bloomington: Indiana University Press, 2005. Detailed study of the role of the imagination in Kant’s philosophy of mind and of its function within his moral system.

Kant, Immanuel. Translated by Werner S. Pluhar and Stephen Engstrom. Critique of Practical Reason. Indianapolis, Ind.: Hackett, 2002. This volume contains a review of translations and their difficulties by Pluhar.

Wilson, E. “Kantian Autonomy and the Moral Self. ” Review of Metaphysics 62, no. 2 (2008): 355-381. Takes Kant to task about some of the concepts that he leaves open. Kant assumed free will, God, and an eternal soul as needed for moral thinking; Wilson presses for answers and clear commitments.