Kant says that human beings tend to do bad things not simply because they have immoral tendencies, but because those tendencies are encouraged by community life. Membership in a community develops a set of negative passions. As Kant puts it, "envy, addiction to power, avarice, and the malignant inclinations associated with these, assail [humankind's] nature, which on its own is undemanding, as soon [we are] among human beings" (6:94). Our interactions with others trigger our immoral inclinations. Kant's interpretation of Christianity is supplemented by this empirical theory of how human nature becomes corrupted. In place of the theory that original sin causes bad human behavior, Kant posits that community life causes bad human behavior.
Kant recognizes that human beings cannot abide by moral principles (maxims) without some way of combating the negative by-products of living in human communities. He believes that church attendance will only partially help people live moral lives. While religious principles can encourage truly ethical behavior, religious customs and communities can encourage the same sort of competition and negativity fostered by social communities. Members of a church congregation can even become competitive about morals, competing to be the most morally superior member of the group.
Kant advocates ethical communities as ways of helping people become moral. A true ethical community is an ideal, something that actual churches aspire to. Ethical communities would differ from religious ones in several ways. Ethical communities are bound by moral principles Kant calls duties of virtue. These duties are applicable to all human beings everywhere, at any time, in any place. The laws of an ethical community are universally binding because, in Kant's view, people are rational and therefore destined to promote the highest common good.
In this section, Kant builds upon his theory of moral religion by explaining his view that social life triggers human immorality. Kant holds that human beings spur each other on to immoral behavior through envy, pride, competitiveness, and a host of other antisocial, counter-productive emotions. These antisocial passions are best counteracted by ethical communities. Religious communities only approximate ideal ethical communities.
Humans are responsible for their bad behavior, even though social interaction incites it. Society might fan the flames of envy and resentment, but in the end humans cannot pass the blame for their immoral choices. They act on their free will when they choose badly; no one is forcing them to adopt immoral principles. We could call Kant an "individualist" on the topic of moral responsibility, because he thinks that evil behavior is always attributable to an individual. Cultural and political institutions help along our evil conduct, but we still author our own behavior.
We might wonder whether our unavoidable tendency to be influenced by our community excuses the immorality that results from that influence. Kant would likely explain that even though we are hardwired to pay attention to society, and even though we have no control over our need to feel accepted, we do have control over resisting the pressure society places on us. We cannot erase the need to feel accepted, but we can resist doing immoral things because we want to be accepted.