New York: Oxford University Press, 2005
Ken Binmore makes it clear from the very beginning of his book, Natural Justice, that one of the central themes of his work would be evolutionary theory. From the first page of the book, Binmore points out the need to treat morality as a science and that the moral rules in human societies are shaped by evolutionary forces. In addition to the evolutionary theory, Binmore also heavily relies on three other theories throughout his book, namely game theory, bargaining theory, and the theory of rational choice. Using these underlying theories, his book is an ambitious attempt at applying mathematical game theory to provide a better understanding of human societies and the social contracts that hold these societies together.
As Seabright aptly points out, Binmore’s Natural Justice combines “the ambition of Rawls” with “the naturalism of Hume” (2006). Binmore adopted the concept of “Original Position” developed by John Rawls and John Harsanyi to support his argument throughout the book. However, contrary to how Rawls used “Original Position” in a theoretically prescriptive way, Binmore considered the concept as a more economic tool (Harms 2012). Binmore is convinced that our sense of fairness is a result of evolution and this sense serves as equilibrium selection devices. The author further shows that these equilibrium selection devices stemmed from “Original Position” can be applied in tandem with Nash’s bargaining theory in order to create social contracts that are sustainable for our society. According to Binmore, such a bargaining process will lead to an equilibrium which contains a mutually agreed on the notion of fairness by the members of society.
The general message Natural Justice sends to the readers is that it is inconsistent with human nature to implement social reforms or contracts that are not stable since such reforms will not bring about equilibrium in the game of life. Here, we need to note that Binmore’s game of life constitutes a series of repeated games. Binmore highlights the need of game theory and economics in order to be able to construct social reforms that will be conducive to human society. Binmore further states that the only productive reforms are egalitarian in nature and they are only possible through planned decentralization. Reforms that are not designed through planned decentralization will lack the three levels of priority for a productive social contract, namely stability, efficiency, and fairness. Hence, such reforms will fail to compete with other forms of social contracts.
Binmore begins Natural Justice by explaining the three levels of priority and social contract in Chapter 1. The second chapter provides an introduction to bargaining theory, its problems, and solutions. Next, Binmore moves on to explain different types of “isms” in Philosophy in Chapter 3 before he begins introducing the readers to the notions of equilibrium in game theory in the next chapter. Binmore digs deeper into game theory when he explains the theory of repeated games in Chapter 5. The next three chapters contain discussions of duty, kinship, and empathy respectively. All three chapters are albeit influenced by game theoretical explanations. Binmore finally introduces the concept of “Original Position” in Chapter 9 as the key notion to understand our sense of fairness in social contracts. Here, he makes a distinctive argument that the use of “Original Position” has evolved from our hunter-gatherer past and thus, we are genetically wired to use the concept. After discussing how to better understand social contracts, in Chapter 10 and 11, Binmore discusses which solutions we should choose to incorporate as a part of the social contract for our society. Chapter 10 explores the case where there is an authority in the society who is capable of enforcing the outcome of the bargaining process. Chapter 11 presents the case in which there is none. Finally, in the last chapter, Binmore pushes his main argument recommending planned decentralization and plausible social reforms.
Natural Justice employs a far less convoluted writing style compared to Binmore’s former works. This relatively clear style of writing allows readers to follow through each chapter without much difficulty. As a graduate student in Political Science, I personally find this book suitable for my course level. However, I also find Binmore’s Natural Justice more technical rather than philosophical. Throughout this book, Binmore attempts to sell the idea of combining theories of justice with game theory in order to successfully produce conducive social reforms and stable social contracts. However, instead of hitting the sweet spot of being neither too theoretical nor mathematical, Binmore’s book leans towards the mathematical side by focusing rather heavily on introducing game theory to the readers.
Before discussing critics of Natural Justice, I would like to point out a central idea of Binmore that I strongly agree with. It is very apparent in his writing that Binmore believes that people are self-regarding individuals, that is, people almost always behave according to their self-interest and altruism is usually performed with the hopes of reciprocity. This aligns with Hobbes’ famous discussion on how a man’s own good is his primary objective, even during the seemingly selfless acts of volunteerism. Building on his belief that people are self-regarding individuals, Binmore suggests designing social contracts that people are still willing and happy to follow without having to go against their self-interested natures completely. Although Binmore’s work drew heavily from some of Rawls concepts, I find Binmore more realistic in his discussion of social contracts than Rawls is.
Amongst the many reviewers of Binmore’s Natural Justice, Sillari (2008) stated that a possible objection to Binmore’s belief in reciprocal altruism could be that this belief presumes all members of a society to be contributing members to the society. However, Binmore already addressed this critic by saying that
“a) tree or an unborn human is powerless, and so can’t be a player in the game of life. Animals, babies, the senile, and the mentally ill are only marginally less helpless, and hence equally unable to take on duties. They are correspondingly unable to exercise any rights under the social contract” (p. 97).
However, this is not the only criticism that Sillari has in mind for Binmore. Sillari’s main disagreement with Natural Justice is “the role that common knowledge plays in conventions and, by extension, in his naturalistic theory of justice” (2008 p. 294). Sillari believes that in Natural Justice, Binmore altogether disregards the role of common knowledge in human societies.
Another critic of Binmore’s 2005 work is Herbert Gintis. While Gintis thinks that Natural Justice is a profound attempt at applying mathematical and economic theories to understanding Justice in human societies, he does not agree with Binmore that moral values can be used empirically as solutions to the Nash bargaining problem. Gintis believes that Binmore went too far carrying out his explanations of social reforms in an analytical economic perspective. He argues that if Binmore’s theory of humans being self-regarding individuals who are yet capable of committing altruism to hold true, then it is ironic that Binmore is using a very structured repeated game theory to design social contracts that could control the behaviors of a large group of such unpredictable creatures (2006). Gintis instead argues that
“human beings are emotionally constituted, by virtue of their evolutionary history, to embrace prosocial and altruistic notions of in-group–out-group identification and reciprocity”
instead of being completely self-regarding creatures as Binmore suggests (2006).
There are also some critics to Binmore’s Natural Justice that brought the attention of Ken Binmore to address their comments at a symposium organized around discussing the 2005 work. The critics Binmore chose to discuss are as follows: de Jasay, Riley, Hardin, Birnbacher, Lahno, Peter, Schmidt-Petri, Cushman, Young, and Hauser, Skyrms, North, Ahlert, and Kliemt. Surprisingly, despite his rather confident tone and writing style in Natural Justice, Binmore agrees with many of his critics. For instance, in addressing Fabienne Peter’s Justice: Political Not Natural, Binmore admits to uneasily agreeing with Peter that naturalist theories are not written by nature but are scholarly attempts to reflect on a select set of data about social life (2006 p. 115). He also agrees with Cushman, Young, and Hauser’s insistence on the importance of process (2006 p. 116).
Binmore’s shortest response to but at the same time, strongest agreement with Brian Skyrms’ Ken Binmore’s Natural Justice stands out among all his responses to the book reviewers and critics. Here, Binmore simply agrees that all the weaknesses of his work pointed out by Skyrms are to the point as well as the overall summary provided on his book. However, Binmore notes that Skyrms’ review, although being agreeable, lacks further research. If further research is done properly, Binmore sincerely believes that it could be positively contributing to the political literature.
Not all reviewers of Ken Binmore’s Natural Justice are strong critics of the author and his work. For instance, Harms (2012) agrees that Binmore’s work is correct about several aspects. One of the aspects Harms agrees with is Binmore’s belief that social reforms should be based on an understanding of the status quo and realistic expectations (2012). Harms also is on the same page with Binmore that economic and mathematical theories, along with game theory applications are the only effective ways to address the issues of social reforms in a precise manner (2012).
Harms is not the only person who agrees with Ken Binmore’s Natural Justice. Another reviewer, Dr. Paul Seabright of the University of Toulouse, France, is also a fan of Binmore’s work. Seabright agrees with Binmore that the norms of social justice have evolved as a part of human social behavior. He also agrees with Binmore that these norms are actually produced as central products of the human evolution instead of merely being the by-products of the process. For these two firmly naturalistic reasons, Seabright wholeheartedly agrees Ken Binmore’s explanations of natural justice is theoretically sound (2006).
After reading both Natural Justice and its reviews by critics of Binmore, I find myself in the middle ground of neither being a fan nor foe of Binmore’s work. As someone who agrees strongly with Thomas Hobbes’ natural state of war and his discussion on the glory-seeking behavior of human beings, I find myself supporting Binmore’s statement that all humans are staunchly self-regarding individuals. However, I do agree with some of Binmore’s critics that in an attempt to combine mathematical game theory with explanations of the nature of human societies, Binmore failed to present a balanced mixture of mathematics and political theory. I find most of his book still very technical, even when Natural Justice is far less game theoretical than most of Binmore’s former works. Regardless of stating that he is not going to rely on mathematical equations and explanations in Natural Justice, Ken Binmore fails to keep his promise. The second chapter of the book makes ample use of geometrical examples while explaining the concepts of Nash bargaining problem and its solutions.
Overall, Ken Binmore’s Natural Justice is an ambitious and well-written account detailing how we can find a better understanding of human societies through the three different lenses of economic, evolutionary, and game theory. The work is brief, yet it manages to succinctly deliver Binmore’s concept of natural justice and his suggestions on how to efficiently design social reforms or social contracts that are sustainable for human society along with impeccable explanations of different game theory concepts. Within the short length of the book, Binmore also manages to draw on the works of other political philosophers such as John Rawls and John Harsanyi.
However, his book also has its limitations. The immense influence of mathematics, economics, and game theory in his explanations of human nature did not sit well with most of his critics. Binmore himself also admitted that some of the speculations in his book are made without reservations and qualifications, thereby somewhat compromising the quality of his work. Last but not least, Binmore stated that his claims “are not proved but illustrated with examples” (2005 p. ix). For these reasons, unlike Seabright, I am hesitant to say that I wholeheartedly agree with Binmore’s Natural Justice. However, I cannot deny that this book serves as a thorough introduction for students who want to apply game theory to the realm of political science and policy making.
- Binmore, K. (2005). Natural justice / Ken Binmore.
- Binmore, K. (2006). Natural justice: Response to comments. Analyse Und Kritik, 28(1), 111-117.
- Gintis, H. (2006). Behavioral ethics meets natural justice. Politics, Philosophy & Economics, 5(1), 5–32.
- Harms, W. (2012). Ken Binmore Natural Justice. Philosophy in Review, 2, 86-88.
- Seabright, P. (2006). The evolution of fairness norms: An essay on Ken Binmore’s Natural Justice. Politics, Philosophy & Economics, 5(1), 33-50.
- Sillari, G. (2008). Natural Justice, Ken Binmore. Economics and Philosophy, 24(2), 287-295.