Natural Justice

by Ken Binmore

This book lays out foundations for a "science of morals." Binmore uses game theory as a systematic tool for investigating ethical matters. He reinterprets classical social contract ideas within a game-theory framework and generates new insights into the fundamental questions of social philosophy. In contrast to the previous writing in moral philosophy that relied on vague notion such as " societal well-being" and "moral duty," Binmore begins with individuals; rational decision-makers with the ability to empathize with one another. Any social arrangement that prescribes them to act against their interests will become unstable and eventually will be replaced by another, until one is found that includes worthwhile actions for all individuals involved.

Genres: Philosophy, Economics, Nonfiction, Science, Politics, Mathematics

224 pages, Hardcover

First published February 17, 2005

About the author

Professor of Economics at UCL, after holding corresponding positions at LSE and the University of Pennsylvania and Michigan. Onetime Professor of Mathematics at LSE.

Author of 77 published papers and 11 books. Research in evolutionary game theory, bargaining theory, experimental economics, political philosophy, mathematics and statistics.

Grants from National Science Foundation (3), ESRC (1), STICERD (2) and others. Chairman of LSE Economics Theory Workshop (10 years), Director of Michigan Economic Laboratory (5 years). Fellow of the Econometric Society and British Academy. Extensive collaboration with 25 co-authors.

Awarded the CBE in the New Years Honours List 2001 largely for his role in designing the UK 3G Spectrum Auction.

Reviews

[Manny · Rating 5 out of 5]

A few weeks ago, I was chatting with Jen when the subject of the Prisoner's Dilemma came up. Jen said she'd read about this and related cases of the Tragedy of the Commons, where a good result could be obtained if people cooperated, but the structure of the payoffs encourages antisocial behaviour that is to everyone's disadvantage. It is indeed depressingly easy to come up with examples: most of the problems facing the world today, from climate change to the toilet paper shortage, are some version of the same problem. Jen said her first reaction had been a refusal to accept that we couldn't do better than this, but after some thought found it was hard to come up with any specific ideas. I had to admit that I was in the same position.

What surprised me most was that, even though the Prisoner's Dilemma is clearly of fundamental importance, I knew virtually nothing about it. I decided I would try to become less ignorant, and after searching around ordered a copy of the 2015 CUP collection. It was a mixed bag; the standout paper was the first one, by someone called Ken Binmore. I'd never heard of Binmore, but the paper was so interesting and well-written that I had to find out what else he'd done. A little more search led me to Natural Justice.

You only have to read a few pages of Binmore to see that he is an extremely smart and well-informed person who's familiar with a wide range of subjects. He tells you he was originally a mathematician, then drifted into economics and game theory. But he's also seriously up to speed on philosophy, evolutionary biology, empirical psychology and political science. The theory he's put together makes use of all of this. Trying to summarise it in a Goodreads review is an impossible task - Natural Justice is itself no more than a popular summary of Binmore's two volume magnum opus, Game Theory and the Social Contract - but let me at least give you a trailer and encourage you to check it out for yourself.

Natural Justice is a work of moral philosophy, but it's not like other moral philosophy I have come across. Up until now, if you'd asked me what moral philosophy was, I'd have said it was about telling you how should live your life, helping you understand which actions are good, right or fair, as opposed to bad, wrong or unfair. Binmore is impatient with all this, and brutally says that we've been discussing such questions for two thousand years without making much progress. He wants to get back to fundamental issues: what do "good" "right" and "fair" mean in the first place? Your reaction may be that this is going to get us into even more trouble, but initial impressions are often wrong. Binmore's plan is simple and logical. Human beings are living creatures who have evolved. In every human society, we use moral concepts all the time, so we must have evolved them. How? What evolutionary strategies do they belong to? Why are they useful to us?

These questions are so natural that I'm kind of shocked I haven't thought more about them. Quite likely there's more than one possible line of attack; Binmore says the one he's developed has its roots in the work of Rawls, Harsanyi and above all Hume, but he's combined their ideas in interesting new ways and gone much further. First of all, for reasons familiar both to economists and evolutionary biologists, he assumes that people are mostly driven by self-interest. (More about the "mostly" soon). Sometimes our interests will come into conflict, and sometimes there will be ways in which we will gain from cooperating. As we can see from the Prisoner's Dilemma, things are not so simple. It'll often be the case that cooperating will gain - but we can't cooperate unless we trust each other, and where will the trust come from?

But as everyone who's looked at the Prisoner's Dilemma knows, if you play it multiple times then people can reach an equilibrium where they all play strategies which make cooperation the rational thing to do: basically, they learn to punish anyone who doesn't cooperate by refusing to cooperate with them. In general, economics and evolution show us that these situations normally end up in some kind of equilibrium. In most cases, there will be several possible equilibria. An example that's used many times in the book is Rousseau's Stag Hunt. Two hunters can each catch a rabbit if they hunt on their own - but if they cooperate, they can catch a stag, and half a stag is much better than a rabbit. There is one equilibrium where they hunt separately, and one where they hunt together. Binmore calls these equilibria examples of "social contracts". The question is how we choose between the different social contracts available, and try to move towards the more efficient ones.

So far, this is just game theory, and it's been done many times before. It gets interesting when Binmore introduces the notion of fairness. Binmore thinks that fairness is something we have in our genes: every society has a version of the Golden Rule, do as you would be done by, and it never needs to be explained. He looks at the hunter-gatherer societies that have survived long enough to be studied by modern anthropologists, and says they all have pretty much the same structure. There are no chiefs (when I read a book on Wangkatja grammar last year, I remember being surprised to find there is no native Wangkatja word for "chief"), and people share the results of hunting fairly. But what does "fairly" mean?

Binmore argues that this is the key, the thing that makes us human; no other species seems to have any notion of fairness. Following Rawls and Harsanyi, he says the observed facts suggest we have an evolved ability to put ourselves in two different people's positions (one of the people might be ourself) and compare them. This is what lets us feel that an arrangement is fair or unfair. We imagine being those two people, and try to decide which role we'd prefer to take. For this to be possible, we need a sense of empathy. Binmore draws an important distinction between "sympathy" and "empathy". He uses "sympathy" to refer to the feelings we have for our family and other people close to us: we care about their well-being in the same way that we care about our own. "Empathy" is the ability to put ourselves emotionally in someone else's position, but without necessarily caring about them. In a nice example, he considers the conman who tricks gullible old ladies out of their life savings. He needs to be good at empathizing with his victims to make the scam work, but he doesn't sympathise with them at all.

Binmore's heroic attempt to develop a formal treatment of empathy, and relate it to fairness, is the centre of the book. He says it's no accident that we easily confuse sympathy and empathy. The fact that they feel similar is most easily explained by assuming that sympathy came first - a great many species care about their kin, for obvious evolutionary reasons - and that the mechanism was gradually adapted by evolution to permit empathy as well. The thing that's so remarkable in his account is the level of detail. Empathy, as conceptualised by Binmore, is a faculty like language. We are all born with an ability to learn language, but how we learn it depends on our cultural surroundings, and is to quite a large extent under our control. I am again surprised that I haven't thought about this before, but it seems perfectly reasonable to say that empathy is the same. Different cultures evidently empathise differently, and within the same culture the rules for empathy change over time. Binmore, who never removes his game theorist hat even when talking about the most philosophical of ideas, relates this to the balance of power between the different agents involved, and provides a detailed analysis of how empathy fits into game theoretic strategic play. If empathy and a sense of fairness were developed by evolution, that can only be because they are fitness-enhancing: they give us more productive ways of balancing power, and as power relationships change then empathy relations also change. Trying to think of concrete examples, the one that occurs to me first is the way women's status has changed in Western society over the last century. Women have negotiated themselves a lot more power, and I think that has indeed changed the way in which men empathise with them.

I have merely scratched the surface of Binmore's remarkable book - which, I should add, is not just thought-provoking but charmingly written and often very funny. If only more philosophy were like this. I must get hold of Game Theory and the Social Contract.
_______________________

[Update, Oct 20 2020]

Binmore continually refers to Rawls, so I thought I should read A Theory of Justice. I was struck by the following footnote in §23:

10. Theory of Games as a Tool for the Moral Philosopher (Cambridge, The University Press, 1955). On the analysis he presents, it turns out that the fair division of playing time between Matthew and Luke depends on their preferences, and these in turn are connected with the instruments they wish to play. Since Matthew has a threat advantage over Luke, arising from the fact that Matthew, the trumpeter, prefers both of them playing at once to neither of them playing, whereas Luke, the pianist, prefers silence to cacophony, Matthew is allotted twenty-six evenings of play to Luke’s seventeen. If the situation were reversed, the threat advantage would be with Luke. See pp. 36f. But we have only to suppose that Matthew is a jazz enthusiast who plays the drums, and Luke a violinist who plays sonatas, in which case it will be fair on this analysis for Matthew to play whenever and as often as he likes, assuming as it is plausible to assume that he does not care whether Luke plays or not. Clearly something has gone wrong. What is lacking is a suitable definition of a status quo that is acceptable from a moral point of view. We cannot take various contingencies as known and individual preferences as given and expect to elucidate the concept of justice (or fairness) by theories of bargaining. The conception of the original position is designed to meet the problem of the appropriate status quo. A similar objection to Braithwaite’s analysis is found in J. R. Lucas, “Moralists and Gamesmen,” Philosophy, vol. 34 (1959), pp. 9f. For another discussion, consult Sen, Collective Choice and Social Welfare, pp. 118–123, who argues that the solution of J. F. Nash in “The Bargaining Problem,” Econometrica, vol. 18 (1950), is similarly defective from an ethical point of view.

What is remarkable is that Binmore, whom I'd been thinking of as virtually a disciple of Rawls, bases his entire theory of fairness on bargaining - but bargaining in the original position. Binmore knew Rawls well, and I'm curious to know if Rawls ever retracted his claim here.

[Fin Moorhouse · Rating 3 out of 5]

"Keep me always at it, and I'll keep you always at it, you keep someone else always at it. There you are with the Whole Duty of Man in a commercial country."
– Mr. Pancks, from Dickens' Little Dorrit

I feel like this quote nicely summarises Natural Justice's sentiment: sell grand moral theories, buy game theory. Binmore unpacks some key ideas from his field (personal highlight: the baffling Centipede game) and shows just how they explain social order. He also argues (convincingly, I guess) that fairness norms are evolutionarily hard-coded. Among other things, this explains why few conflicts are more heated than squabbles with siblings about who got more sweets / pocket money / TV time.

Binmore is also a card-carrying, flag-waving moral relativist, and spends the remainder of the book trying to explain what game theory supposedly tells us about ethics. He does a good job at making his extra-naturalistic perspective sound fairly sane (or at least non-egregious); though at times it felt like he was reacting to SparkNotes summaries of the headline moral theories he wanted to set himself apart from. When, asks Binmore, will these blockheads stop searching for 'skyhooks' from which they can hoist their universal pronouncements about the Right and Good? As a heuristic: be wary when every other candidate view seems equally insane!

I'm actually not sure how much I got out of this. Very often, I got the impression Binmore was dressing up some fairly innocuous observations as piercing and/or damning insights. On the other hand, the mark of good philosophy is often precisely that it sounds innocuous and obvious in retrospect—when the writing is clear enough that you feel like you knew it all along. Shelved as 'to-reread'. Maybe Game Theory and the Social Contract will clear things up.

[S. · Rating 4 out of 5]

All in all, a fascinating book to read for its arguments alone.

What Binmore is trying to advocate in the book is a move away from a metaphysical explanation of morality to a scientific one. His thesis is that through biological and cultural evolution, humans have a hardwire device in our genome that allows us to make judgments of justice and fairness (morality). As such, morality is not rationally conducted, nor does it come about by God-given reason, rather it is found in the human genome.

Obviously the book has a couple of flaws with the actual validity of the argument, but it is a fascinating, thought provoking argument.

[Hoho Ghumpus · Rating 3 out of 5]

The ideas are brilliant--an attempt to rigorously apply evolutionary theory to social interactions (and thus politics), via the tools of game theory--but much more clearly explicated in the two-volume Game Theory and the Social Contract books by the same author. In an attempt to avoid equations, Binmore makes the material more difficult to understand. I applaud the effort, but the writing doesn't quite get there.

[Hoho Ghumpus · Rating 3 out of 5]

The ideas are brilliant--an attempt to rigorously apply evolutionary theory to social interactions (and thus politics), via the tools of game theory--but much more clearly explicated in the two-volume Game Theory and the Social Contract books by the same author. In an attempt to avoid equations, Binmore makes the material more difficult to understand. I applaud the effort, but the writing doesn't quite get there.

[Fabian · Rating 2 out of 5]

I found zero value reading trough 2/3 of the book ... I like the author but think he should stick to Game Theory.

[Morris Yen · Rating 4 out of 5]

a bit hard to comprehend

[Igor Razvodovsky · Rating 5 out of 5]

Natural Justice starts with criticism of moral philosophy and its endless (and more importantly fruitless) contemplation of Right and Wrong. Instead, Binmore approaches morality from the point of view of economics, game theory, and evolution (both biological and cultural) and to my (admittedly poorly educated) eye does it really well.

The idea is simple. Moral concepts are used by all people, so we must have evolved them → Anything that evolution works on is useful → Why morality is a useful adaptation?

The assumption is that people are mostly driven by self-interest. Sometimes our interests come into conflict, and sometimes there will be ways in which we will gain from cooperating. Prisoner's Dilemma shows that things are not so simple. It shows how cooperation is "irrational". This is solved by repeated games – playing multiple times makes cooperation the rational thing to do: people learn to punish anyone who doesn't cooperate by refusing to cooperate with them. In general, economics and evolution show us that these situations normally end up in some kind of equilibrium – social contract. In most cases, there will be several possible social contracts. The question is how we choose between the different social contracts available, and switch to the more efficient ones?

Hypothesis is that fairness is the key and this is something we have in our genes. We have an evolved ability to put ourselves in other people's places and compare them. We imagine being another person, and try to decide which role we'd prefer to take. For this to be possible, we need a sense of empathy. Binmore differentiates between sympathy and empathy. Empathy according to him is the ability to put ourselves emotionally in someone else's position, but without necessarily caring about them.

Empathy is similar to language, i.e., we are born with the ability to learn it, but how we learn it depends on context → different cultures empathise differently.

Another important aspect is that sense of fairness evolved (and was optimised) for solving day-to-day who-goes-through-the-door-first problems. We notice moral rules only when trying to apply them to large scale problems.

This provides a more realistic expectations of what is possible when it comes to human “betterment“

[Rinstinkt · Rating 1 out of 5]

Totally disappointed with this book and author. He started well, but after the initial presentation of the topic things went south. I expected a book purely on morals and ethics from a game theory and/or evolutionary perspective, but half the worlds he has written are pure gibberish. He reprimands some thinkers (and I tend to agree on that), but then himself does the same error. Masking his own preference as science. Instead of simply describing the uncontested facts of this field of inquiry, which are actually pretty rare and scattered here and there, but again, mostly rare, he wastes entire paragraphs into denigrating certain thinkers. And, I repeat, on a factual basis the discontent he has towards those thinkers is ok, but he doesn't make a good job explaining it.

I tried to go on, and finish it... But then, at 30% in, I read this passage, and I totally agree with the observation:

The naturalistic views expressed in this book are often attacked as dehumanizing or dispiriting. Do our lives really have no meaning? Are we no more than soulless beasts, like apes or robots? People often refuse to believe that anyone could really hold such supposedly bleak views on the nature of human existence. What would be the point of going on with life if such things were true? One answer is that Nature doesn't care whether we like her truths or not.

But then the author writes:

It is sometimes argued that the state of nature in a social contract problem should be identified with a game. The Prisoners' Dilemma is popular in this role with political philosophers who are influenced by the misanthropy of Thomas Hobbes.

Totally non-coherent. Calls Hobbes a misanthrope because he doesn't like his reasoning or conclusions. No further explanation. Ridiculous!

Btw, I'm pretty well-read about evolutionary perspectives in a lot of different topics (and I fully endorse these), so his sparse sentences supporting evolutionary observations for his own interest aka inflating the relevance of the book in a way, had the opposite effect on me.
Shocked that this is one of his best books. Total garbage!