The title of this book by Philip Pettit points to an intriguing and important question. As the subtitle has it, the goal of the book is "reconstructing the role and nature of morality." It attempts to analyze how ethics came into being. How did humans invent, or discover, ethics? A description of how ethics fits in with human evolution could potentially tell us a lot about both humans and ethics. But the way this book goes about it does not, in my mind, deliver the goods. The starting point is not very believable, and the explicit constraints put on the narrative by the author do not help. The result is disappointing. In fact, the most useful part of the book is the criticism of its main text by Michael Tomasello in a short section at the end.
The narrative begins with Erewhon, a hypothetical human society in which people can communicate by natural language, but in which ethics or morality as such does not exist. Pettit is explicit that this is a thought experiment. Erewhon has not actually existed. The question Pettit poses is: Given this state, how has ethics emerged? In my mind, this makes his narrative vulnerable to the same kind of criticism that can be leveled at John Rawls theory of justice, or for that matter at any hypothetical tale of how a social contract has been arrived at. The starting point is always open to criticism: Why define the starting point in exactly those terms? There is always the worry that the starting point has been designed to produce the justification of a particular moral theory that one desires. That is, the argument is not really a derivation from axioms, as it purports to be, but rather a construction of a particular set of axioms that gives the requested result.
Pettit posits several constraints on the narrative: it must be naturalistic, i.e. it cannot invoke any supernatural interventions. Fair enough; we are not interested in yet another explanation of ethics that tries to avoid Euthyphro's dilemma as stated by Plato. Another constraint is that the narrative must not rely on luck. Pettit view is that the emergence of ethics from within Erewhon must be a process that more or less inevitably had to follow. To rely on luck for this process to occur would be a kind of cheating, is my interpretation. To some extent, I can understand why Pettit imposes this constraint. But this unfortunately means that the theory will be proving too much. Evolution, in actual fact, and the emergence of novel features that it entails, contains an essential component of randomness, luck if you will. At no point in the evolutionary history of the ancestors of us humans was it inevitable that Homo sapiens would emerge. Therefore the idea that a narrative of how ethics emerged must rely on inevitability is too strong. It proves too much.
Tomasello's criticism of Pettit's text relates to the issue of cooperation. When Pettit starts his narrative with the existence of human language as a means of communication, Tomasello asks whether it is not in fact cooperation that was the starting point for why we even invented language. In his view, morality starts with the problems caused by cooperation, and language is a secondary issue in that respect. I notice that the cover of the book shows a painting "Group of five men working with a net". The men are not primarily talking, they are collaborating.
The book is not easy text to read. At times, it seems that there is no progress in the argument, simply a stating and restating of a number of thesis, again and again. It has a number of words that recur in a vast array of permutations, such as "desiderata", "avowal" and "pledging". There is a lot of splitting up of issues into multiple subarguments in ways that do not contribute to clarity. Given the weakness of the argument, I cannot really recommend it.