Summary of Kant’s Theory of Human Nature

(I am teaching the course “Philosophy of the Human Person” at a local university. These are my notes of the primary text for the course, Twelve Theories of Human Nature. )

Immanuel Kant (1724 – 1804) is generally considered one of the three or four greatest philosophers in the Western tradition. He lived his entire life in Konigsberg, Prussia which is today the city of Kaliningrad in Russia. Kant’s philosophy is extraordinarily complex but perhaps he was most interested in reconciling Christianity with the science of the Enlightenment.

Kant was quite an accomplished scientist who “developed the nebular hypothesis, the first account of the origin of the solar system by accretion of the planets from clouds of dust.” His education in the humanities was equally impressive “embracing Greek and Latin philosophy and literature, European philosophy, theology, and political theory.” In his university education he was particularly influenced Leibniz, a rationalist who believed that pure reason could prove metaphysical claims, especially those about the existence of god and that we live in the best of all possible worlds. Thus both empiricism and rationalism influenced him, and he spent a lifetime trying to reconcile them.

Kant was the deepest thinker of the European Enlightenment who believed “in the free, democratic use of reason to examine everything, however traditional, authoritative, or sacred … He argued that the only limits on human reason are those that we discover when we scrutinize the pretensions and limitations of reason itself …” His emphasis on the inquiry into the nature and limits of human knowledge meant that epistemology became for him the heart of philosophy. He turned his critical analysis to science, metaphysics, ethics, judgments of beauty and to religion.

Metaphysics, Epistemology, and the Limits of Human Knowledge – A fundamental theme of Kant’s philosophy “was to explain how scientific knowledge is possible.” He argued that “science depends on certain fundamental propositions, for example, that every event has a cause and that something (substance) is conserved through mere change.” These principles cannot be proved empirically but they are not tautologies either. [In Kant’s language they are synthetic a priori propositions—propositions whose predicate concept is not contained in its subject concept but related, and propositions whose justification does not rely upon experience. An example of a synthetic proposition is “all bachelors are unhappy.” An example of an a priori proposition is “all bachelors are unmarried.] Many philosophers of the time including Leibniz and Hume, as well as many philosophers today deny the possibility of such propositions.] Kant believed that these synthetic a priori propositions “can be shown to be necessary conditions of any self-conscious, conceptualized perceptual experience of an objective world. [In other words we can’t have experiences of the world without assuming these propositions are true.]

In the first part of his magisterial Critique of Pure Reason, Kant sets out his theory of how we perceive everything in space and time, and the twelve categories or forms of thought and associated concepts like substance and causality. This leads to the justification for Kant of empirical (a posteriori) knowledge derived from sense experience, and analytical (a priori) knowledge derived from pure reasoning. And, as we saw in the previous paragraph, he also argued that there exist synthetic a priori propositions. Kant famously argued that much of mathematics is in this 3rd box, although many philosophers would argue that mathematics is analytic. Most importantly Kant accepts the existence of an independently existing material world. [Kant is arguing, among other things, that mathematical and scientific knowledge are justified.]

Still Kant argued that how we perceive this external world depends on how the inputs of that world are processed by our cognitive faculties and sensory apparatus. This implies that our cognitive intuitions may “distort our representation of what exists.” And this means we know the world only as it appears to us, not as it really is. Furthermore things as they really are may not even be in space and time! [Thus Kant’s Copernican revolution. We are at the center of our reality, structuring it with our minds; our minds are not passive receptors of the external world.]

In the second part of the Critique of Pure Reason, Kant argues that “reason tries to go beyond  … its legitimate use, when we claim illusory metaphysical knowledge … ( human souls, the universe as a whole, uncaused events, and God.) Such claims go beyond the bounds of human knowledge … we can neither prove nor disprove them; we cannot even acquire probable evidence for or against them.” Thus a decisive break with natural theology. [For Kant theology is not an intellectually justified discipline.] Of course many theologians have responded with fideism (religious belief is justified by faith) but, as we will see, Kant is not in this tradition.

Theory of Human Nature – As we have seen Kant was basically interested in reconciling morality and religion with science. How does human nature fit into this project? For Kant perceptual knowledge depends upon the interaction of “sensory states caused by physical objects and events outside the mind, and the mind’s activity in organizing these data under concepts …” Thus humans interact with the world with their senses and their understanding (reasoning and language.) Reason also plays a special role for human beings—they use it to integrate all their knowledge, in “the scientific search for a unified theory of all natural phenomena.”

In addition to abstract theorizing, reasoning also plays a practical role in Kant’s philosophy. We are agents who do things, who act in the world. But there are not merely causes for what we do, as there are for our non-human animal brethren, we also give reasons for what we do. Sometimes the reason we do thing involves our desires which Kant labels “hypothetical imperatives.” [If you want to be a lawyer, then you ought to go to law school.] But at other times, Kant argues, the reasons for our actions command us independent of our desires as in our moral obligations. We ought to tell the truth or help others even if lying or ignoring them would be in our self-interest. These are examples of what Kant calls “categorical imperatives.” [You ought not lie, even if lying would satisfy some desire you have.] Reason recognizes these categorical imperatives which are the basis of ethics [suicide and lying are bad; helping others and developing your talents are good.]

So what does all this mean for his conception of human nature? Are we dualistic or merely material? Kant leaves the question open, it is irresolvable. [Whether the soul is immortal or not; whether we are free or determined, whether the world in infinite or not, all of these Kant calls “antinomies of reason.” That is we can use reason to support either view.] Kant is perhaps most interested in freedom. As for our biological bodies, we are just as determined as other things in the physical world, but because we are rational beings we can act for reasons. We can thus be free. [If we are entirely material beings, this solution probably doesn’t work.] Of course while we can see that my reasons give me a reason to act, it is hard to see how rational propositions give me a reason to act. [The latter is what the categorical imperative claims.] Kant does not solve the problem of freedom—nobody else has either—but he does believe that we act “under the idea of freedom.” That is from a practical we necessarily presuppose that we are free. [And the ethical point of view presupposes freedom as well.]

Diagnosis – Selfishness And Sociality – Kant contrasts non-human animals, who have desires but no sense of duty, and humans who do experience tension between their (self-interested) desires and the demands of the practical reason to do their duty. But how can the interests of others, motivate us to act? Why should we be moral?

Kant argues that reason demands that we be moral. It is our duty to act according to morality rather than our self-interested inclinations and passions. Rational persons should conform their (free) wills to the moral law, which is known to reason through general maxims like the categorical imperative. Being moral is a matter of having the right intention—to follow the moral law—and has nothing to do with the consequences of our actions. We follow the moral law—for example by telling the truth—and disregard whatever consequences may follow. But many people subordinate moral duty to their inclinations, to the desire for their own happiness. Such persons violate the moral law.

As for the source of this immorality, Kant believes on the one hand that we freely choose to disregard our duty, but on the other hand the propensity to evil is somehow innate. The extent to which our evil tendencies are exacerbated by society is open to debate. [What we can say is that something is amiss in human life. We have a duty to others, but we are naturally self-interested.]

Prescription: Pure Religion and Cultural Progress – How then do we overcome selfishness and act morally? Kant dismisses self-interested reasons to be moral—you will be punished if you don’t act appropriately—because such reasons are inconsistent with virtue. For Kant the only thing that is completely good is a good will, the desire or intention to do good for the sake of goodness alone. [While Kant believes the moral law ultimately comes from god, he doesn’t emphasize this. Rather he appeals to human reason’s ability to know the moral law. Furthermore, Kant argued vehemently in the first critique that the traditional arguments for god’s existence were worthless. Yet he will not rely on fideism either. So where does he go?]

What Kant takes with one hand he gives back with another. While pure reason cannot support the existence of his god, the practical reason can justify beliefs in god, the immortality of the soul, and free will. When we act we presuppose that we are free, and saying one ought to do something implies that they can. What then of god and immortality? Kant argues that the highest good, the end of all our striving, is a combination of moral virtue and happiness. Yet morality is not always rewarded in this life and the evildoers often flourish while the good do not. Thus we need god to rectify the situation. God’s perfect justice will reward and punish. [This is basically the moral argument for god’s existence. 1) There is a moral law, thus 2) there must be a moral lawgiver.] It is important that we have hope that moral virtue will be rewarded, although we are moral not because of these possible rewards, but because being moral is our duty. While Kant did not take a lot of religious imagery literally, but he did hope that justice somehow prevailed. He also thought that practical reason justifiably invokes

Kant also “envisaged continued progress in human culture through education, economic development, and political reform, gradually emancipating people from poverty, war, ignorance, and subjection to traditional authorities … he was a supporter of egalitarian and democratic ideals … [and] he sketched a world order of peaceful cooperation between nations with democratic constitutions.” And Kant expressed hope that human potential could be gradually fulfilled. He was a consummate Enlightenment thinker.

ADDENDUM: BASIC IDEAS IN KANT’S PHILOSOPHY (not from the book we are discussing)

WHAT CAN WE KNOW? (addressed in The Critique of Pure Reason)

  1. Mathematics? Yes, it is legitimate knowledge
  2. Natural science? Yes, it too is legitimate knowledge
  3. Metaphysics? No, we can’t know “things-in-themselves,” we can’t know the nature of ultimate reality, reason isn’t justified in making metaphysical claims.

Still, we want a complete picture of reality, despite the fact that theoretical reason can’t give it to us. This is in part because there exist “antimonies” of reason, the most important of which are the existence of: God; freedom; and immortality. Reason cannot resolve such questions. So what do we do when it comes to action? The realm where ethics applies?

WHAT SHOULD WE DO? (addressed in The Critique of Practical Reason)

First we must presuppose the existence of God and freedom for their to be ethics. Since we have reason and free will we can choose between actions, unlike non-human animals who are guided by instinct. For Kant moral actions are actions where reason leads, rather than follows, instincts. Put more simply we ought to conform our free will to the moral law; that is our duty. The moral law ultimately comes from God but Kant doesn’t stress. Instead he emphasizes that reason can overcome our impulses, the non-rational, instinctive part of our nature, by exercising reason.

Thus Kant says that the only thing that is completely good is a good will, one that tries to conform itself to the moral law which is its duty. This presupposes that we are free to do this. But what do we do when we freely conform our will to the moral law when doing our duty? Kant, as an Enlightenment rationalist, assumes that there must be some rational representation of the moral law that we can all understand. And when he thinks about law, say a physical law, one of the key characteristics of true laws of nature are that they are universal. Thus, the moral law must be characterized by its universality. Just as an equation of the form a(b+c) = ab + ac is universally applicable and needs only to be filled in by numbers, the moral law must have an abstract formulation to be filled in by actions.

This leads to the 1st formulation of the categorical imperative (CI), which is the moral law as understood by reason. This law is binding on all rational being and is such that violation of the moral law also violates reason. He gives four examples of actions that demonstrate how the CI works: lying, suicide, helping others and developing your talents. These are all absolute duties, however the first two are perfect duties while the second two are imperfect duties. This means that satisfying one’s duty in the first two cases can be specified exactly, whereas in the other two there are various ways of doing one’s duty. But the key idea is that one’s duty is the rational action, the one that reason demands. Rational actions are moral actions; irrational actions are immoral ones.

Of course, we can act contrary to reason because we are free, just like we can say that 2 + 2 = 6, or round squares exist, or that there are married bachelors. But we violate reason when we say these things just as the bank robber violates reason when he robs banks. Why? The reason is the same as it is for suicide or lying. One cannot consistently universalize the maxim of one’s actions when one engages in such actions. For example, a bank robber wills a world where:

  1. banks exists as the necessary prerequisite of the bank robbery intended and
  2. banks don’t exist as the obvious consequence of bank robberies.

This is Kant’s essential idea. It violates both reason and ethics to say that I can have a drink of your beer but you can’t have a drink of mine.

To summarize, ethical conduct is that in which the will conforms to the moral law which it understands as the CI and this is its duty. Does this lead to happiness? Not necessarily. Kant says if you want to be happy follow your instincts; if you want to be moral follow the constraints of reason. In this way you should see that Kant doesn’t care about the consequences of actions. Do your duty and whatever happens, happens. So the key is your intention which should be to follow the moral law. Note that this intention is internal to the moral agent, not external like consequences are. You should give someone the correct change—in Kant’s example—because it’s the right thing to do, not because its good for business.

Kant’s criticisms of utilitarianism warrant a separate discussion. Utilitarian moral theories evaluate the moral worth of action on the basis of happiness that is produced by an action. Whatever produces the most happiness in the most people is the moral course of action. Kant has an insightful objection to moral evaluations of this sort. The essence of the objection is that utilitarian theories actually devalue the individuals it is supposed to benefit. If we allow utilitarian calculations to motivate our actions, we are allowing the valuation of one person’s welfare and interests in terms of what good they can be used for. It would be possible, for instance, to justify sacrificing one individual for the benefits of others if the utilitarian calculations promise more benefit. Doing so would be the worst example of treating someone utterly as a means and not as an end in themselves.

Another way to consider his objection is to note that utilitarian theories are driven by contingent inclinations in humans for pleasure and happiness, not by the universal moral law dictated by reason. To act in pursuit of happiness is arbitrary and subjective, and is no more moral than acting on the basis of greed, or selfishness. All three emanate from subjective, non-rational grounds. The danger of utilitarianism lies in its embracing of baser instincts, while rejecting the indispensable role of reason and freedom in our actions.

WHAT CAN I HOPE FOR? – I’ll leave this question for another day. But what I hope is that life is meaningful, that it all somehow works out for the best, that a better reality comes to be. Here is my own poem to describe the situation:

And so the world goes on,
good gods perpetually sleeping,
good people perpetually weeping,
and waiting, for a new world to dawn.

2 thoughts on “Summary of Kant’s Theory of Human Nature

  1. Kant is considered to be one the the three or four greatest philosophers in Western tradition. His philosophy was extremely complex but that could be due to his interest in reconciling Christianity with the science of the Enlightenment. He developed the nebular hypothesis which is the first account of the origin of the solar system by accretion of the planets from clouds of dust. Empiricism and rationalism influenced him which resulted in him trying to reconcile them.

    Kant argued that the only limits on human reason are those that we discover when we scrutinize the presentations and limitations of reason itself.

    A fundamental theme of Kant’s philosophy was to explain how scientific knowledge is possible. We can’t have experiences of the world without assuming propositions are true. Kant had this theory of how we perceive everything is in space and time. Empirical knowledge is derived from sense experience. Whereas, analytical knowledge is derived from pure reasoning. Kant argued that mathematics and scientific knowledge belong in the third box due to the reason that they can be justified.

    We know the world as it appears to us, not as it really is. I personally think that this is strong. My niece was born with cataracts. She didn’t have surgery to correct her vision until she was 7 years old. That means that for the first seven years of her life, she was experiencing the world through her perception. After the eye surgery, she began to experience the world in a different perception. She didn’t know the world any other way until her eye surgery. We know the world as it appears to us. Humans interact with the world with their senses and their understanding. Humans use reason to integrate all their knowledge.

    Kant says that we act under the idea of freedom. We are rational beings, so we act for reasons unlike other things in the physical world.

Leave a Reply

Your email address will not be published. Required fields are marked *