What Deontology gets right

Let me preface this with an acknowledgement that Deontology has blind spots and that I’m not a Deontologist. Much like Logical Positivism, however, Deontology has good things to learn from that many Consequentialist decision algorithms miss.

Social Considerations

Your decision has consequences outside of the direct results. More specifically, if you decide to tell a lie, people are more likely to view you as a liar. This portion of consequences are easy to neglect when making a decision. So while Deontology over-corrects for this (for example, if you put a gun to my head and demand that I profess belief X, I’m going to say that I believe X, which a Deontological prohibition against lying forbids), it does so in a way that is better than many people’s naive consequential thinking.

Deontological arguments are also better at convincing people that you have socially valued traits. People expect truth-tellers to tell the truth, so you want to be viewed as a truth-teller. “Lying doesn’t work, so I don’t lie” is a more awkward and involved argument than “lying is wrong”. On a related note, Deonotological reasoning is easier for other people to model. Deontology can screen off the cost-benefit analysis that someone makes when thinking about their decisions, since all you need is the rules that they are following.

Habits and Policies

Decisions aren’t made in a vacuum. They also form an implicit rule that people tend to follow. In other words, people form habits. They find it easier to do the same kinds of things that they’ve always done. Eating one piece of cake doesn’t do measurable harm to your waistline, but having a policy of eating one piece of cake whenever you want to does.

If you’re familiar with set theory, it’s the distinction between {x|P(x)} and {x1, x2, x3...}. If you make decisions without consulting what policy P(x) you’d like to follow, you can make mistakes. Choosing x1 means not only having done x1, but also choosing a P(x) such that P(x1) is true.

When I sign a gay marriage petition, it doesn’t just increase the chance that gay marriage gets enacted. It also makes me more likely to do other things that support the gay marriage movement, as well as make me more likely to sign worthwhile-sounding petitions in general. This is part of why I avoid social movements: trying to fight rape culture or conservatives or racism means that I’m more likely to do similar kinds of things when they don’t help (Or alternatively, convince people to join whatever movement in question even when more support for that movement isn’t helpful).

In short, the Deontological focus on following rules can help people enact the kinds of policies that they want to follow, even if they are bad at evaluating the value gained from following certain policies. It’s a way of implementing a Schelling point, in other words—a way to choose a better policy even if breaking the policy this one time seems to work better.

Enforcing pro-social behavior

It’s fairly straightforward to tell whether or not someone has crossed an arbitrary line separating pro-social and anti-social behavior. Evaluating someone’s consequentialist reasoning, on the other hand, is much more difficult. Let’s take, for example, the case of Christopher Dorner, the former LAPD officer who decided to expose and fight what he saw as a corrupt LAPD by declaring a personal war on them. A Deontological “don’t kill cops” definitively indicts him as anti-social, whereas it’s much more ambiguous whether or not trading some dead cops for a better police force is a good deal or not.


Pro-social reasons for selfish actions are also rather cheap to make or say. If you want a millionaire lifestyle, it’s easy to say that your immoral business practices are for feeding starving children in Africa. It’s a lot harder to say that your immoral business practices don’t violate the rule “don’t use immoral business practices”. In general, rule-breaking is much easier to detect than utility functions you don’t want to have around.