Political Philosophy Spring 2024

The Laws of Nature


Today’s reading presents what Hobbes calls the laws of nature. This is his moral philosophy. He seeks to make two points about the laws of nature:

  1. They are valuable because they are the rules that people have to follow in order to live in peace.

  2. What they require individuals to do depends on how others behave.

You can see how the two points are related. If the laws of nature are rules that people have to follow if there is to be peace and others are not following the laws, then there will be no peace and so no point in following the laws yourself.

You might ask “Why does he have a moral theory at all? Isn’t this political philosophy?” And that would be a very good question. Why not just go straight from “anarchy (aka the state of nature) is bad” to “the state (aka the commonwealth) would be better”?

What is in chapters 14 and 15?

People in the state of nature are not stupid. At least, they are no more stupid than we are. There is an obvious solution to their problem: make a non-aggression pact! I promise not to attack you so long as you do not attack me and vice versa. That would take care of diffidence and “anticipation.” Once they have that worked out, they can make some property rules to make progress on competition as a cause of conflict. And if they are really ambitious they can make some rules about the use of violence to dampen fighting motivated by glory.

Chapters fourteen and fifteen are about how that might work. The most important part concerns what Hobbes calls covenants. These are promises in which one side is trusted to do its part in the future. If I say “pay me tuition in August and I will deliver a lecture on Hobbes in February,” I have made a covenant: you have to wait for me to do my part.

More importantly, if I say “I will not sneak up on you at night so long as you do not threaten me,” I have also made a covenant. You are relying on my keeping my end tonight, tomorrow night, the next night, and, well, every night into the indefinite future. We probably want to throw in the daytime as well. You get the idea.

Chapter fifteen also has some rules about maintaining a peace established by covenants. There are rules about behavior that could upset the peace in ways that are not specific enough to cover in an agreement. For example, you should show gratitude and not take more than you need (15.16-17). There are rules about enforcing the rules in ways that will not cause the system to collapse in cycles of revenge (15.18-19). And there are rules for using arbitrators to settle disputes about deciding when the rules have been broken and about how to punish those who break the rules (15.23f).

In sum, what we have here are rules for establishing peace without the state. They are laws “of nature” rather than laws of the commonwealth.

So why do we need the state?

If the laws of nature are so great, why do we need the state?

Well, remember the second point: what the laws of nature require depends on how others behave. If others are not keeping the laws of nature, you do not have to do so either. Hobbes is quite clear about this: see 15.36. In the state of nature, you cannot count on anyone’s keeping the laws of nature.

To see why, let’s go back to the problem of diffidence. People in the state of nature are in what is called a prisoner’s dilemma (I will explain the name in an appendix below). Here is a representation of that.

Row Column Anticipate Wait Anticipate Wait 3rd 3rd 1st 4th 2nd 2nd 4th 1st Hobbes on anticipatory violence in the state of nature

There is only one stable set of choices here: the northwest box (Anticipate, Anticipate). Suppose they start in the southeast box (Wait, Wait). Row will move to the northeast box (Anticipate, Wait) because first is better than second. Then Column will move from the northeast box to the northwest box because third is better than fourth.

We would reach the same result going the other way. Suppose we start in the southeast box (Wait, Wait) as before and that Column moves to the southwest box (Wait, Anticipate) because first is better than second. Row will push into the northwest box (Anticipate, Anticipate) because third is better than fourth.

In essence, whichever one is getting the fourth best outcome from waiting while the other is anticipating will switch to anticipating instead.

That is the problem: they are in a situation where each of them has an incentive to begin a war with the others. The obvious solution is to establish a non-aggression pact. I promise not to attack you by surprise so long as you do the same for me. Now, having made our covenant, we each face a question every day: should I keep it or break it?

Guess what the incentive structure looks like!

Break Keep Break Keep Hobbes on keeping covenants in the state of nature

If we did not trust one another before we made the non-aggression pact, it is hard to see how we are going to trust one another to keep it. Remember that the cost of misplaced trust can be very high. It can be the last mistake you ever make. (If that does not sound so bad, think about it for a second.)

Without a working non-aggression pact, the rest of the laws do not matter very much.

The upshot is that we are not getting out of war in the state of nature without an actual state to threaten us if we ever try to leave the southeast box. That’s the only way it is going to work.

The good news is that once we have a state in place, we get to enjoy the kind of life made possible by the laws of nature. Hobbes assumes that most people will comply if they can do so safely. And if they try to cheat, the state will be there to suggest they reconsider. In that sense, morality depends on the state.


If morality depends on the state, does that mean that nothing is wrong among people who do not live in a state with one another? It sure seems to (see 14.4). That is hard to swallow. You cannot do anything wrong to another person until you share a state? Yikes.

You will be relieved to know that he wavers on this point. For example, he was convinced that cruelty was always wrong and he took a couple not very convincing stabs at reconciling this with his theory (see chapter 15, paragraph 19 for one).

Hobbes also wavers on the central case for his theory: covenants. He says that covenants are invalid when one party to the covenant fears that the other will not do its part (14.18).

You would think that this is always true in the state of nature: you always fear the other side will break its word and no covenants are valid. Hobbes says this himself (15.3, for instance).

But he also says the opposite. For instance, if you are captured in a war and agree to pay a ransom provided you are released, your agreement is valid and you are obliged to pay (14.27). Hobbes also takes a shot at a Ring of Gyges kind of case involving a character he calls the Fool (15.4-5). The Fool asks why he should keep his covenants if he can get away with breaking them. Hobbes tries to show that he should keep them. The idea is that if the Fool does not keep his word he will not have the allies that he needs to survive in the state of nature. Potential allies will think “he is promising to defend me if I am attacked provided I promise to defend him if he is attacked, but I do not believe that he will do what he promises so there is no point to my making this covenant.” This is OK as far as it goes but it does not really explain why the Fool should keep his covenant if he knows he can get away with breaking it. But leave the question of how successful the argument is to one side. The attempt to explain why people should keep their covenants in the state of nature makes sense only if covenants can be valid in the state of nature. Otherwise, there is nothing to keep! To put it another way, the Fool’s potential allies are obviously keeping their covenants. If they were not, there would be no cost to being excluded from an alliance with them.

Why is he so wobbly about this?

Main Points

  1. Why covenants are an obvious solution to the problems faced by people in the state of nature.

  2. Why covenants are obviously not a solution to the problems faced by people in the state of nature.

  3. Why you can make a case for thinking that Hobbes did think covenants were valid in the state of nature.

Extra: Why is it called a prisoner’s dilemma?

The name “prisoner’s dilemma” comes from a case used to illustrate it. A prosecutor offers two prisoners a deal. “If you give me enough evidence to convict the other guy, he will get an eight year sentence and you will go free. If neither of you give me any evidence, I will be able to convict both of you on a lesser charge that carries a two year sentence. But if both of you give me enough evidence to convict each other, you will each get five year sentences.”

Prisoner R Prisoner C Talk Don't talk Talk Don't talk -5 -5 -0 -8 -2 -2 -8 -0 Prisoner's dilemma, with prisoners

When people are in a prisoner’s dilemma, there is only one stable solution: the northwest (upper left) one. This reflects the fact that they each have what is called a dominant strategy, namely, a choice that is better no matter what the other one does.

In this case, the dominant strategy is to talk. For instance, if Prisoner C (C for column) decides to talk, Prisoner R (R for row) will be better off talking too because a five year sentence (-5) is better than an eight year sentence (-8). And if Prisoner C decides to stay quiet, Prisoner R will be better off talking since no sentence (-0) is better than a two year sentence (-2). If we did the same thing with Prisoner C, we would get the same answer: it makes sense to talk no matter what Prisoner R does. Since both are better off talking than staying quiet no matter what the other one does, they will wind up in the northwest box even though they would obviously be better off in the southeast box.


Hobbes, Thomas. (1651) 1993. Leviathan. Edited by Mark C. Rooks. British Philosophy: 1600-1900. Charlottesville, VA: InteLex Corporation.