The nature and significance of social ontology.

We propose a bridge-builder perspective on social ontology. Our point of departure is that an important task of philosophy is to provide the bigger picture. To this end, it should investigate folk views and determine whether and how they can be preserved once scrutinized from the perspective of the sciences.

Consistent preferences, conflicting reasons, and rational evaluations.

Bermúdez's arguments in favour of the rationality of quasi-cyclical preferences conflate reasons, desires, emotions, and responses with genuine preferences. Rational preference formation requires that the decision-makers not only identify reasons, but also weigh them in a coherent way.

Bargaining power and the evolution of un-fair, non-mutualistic moral norms.

Mutualistic theory explains convincingly the prevalence of fairness norms in small societies of foragers and in large contemporary democratic societies. However, it cannot explain the U-shaped curve of egalitarianism in human history. A theory based on bargaining power is able to provide a more general account and to explain mutualism as a special case.

Strong reciprocity is real, but there is no evidence that uncoordinated costly punishment sustains cooperation in the wild.

I argue in my target article that field evidence does not support the costly punishment hypothesis. Some commentators object to my reading of the evidence, while others agree that evidence in favour of costly punishment is scant. Most importantly, no rigorous measurement of cost-benefit ratios in the field has been attempted so far.

Reciprocity: weak or strong? What punishment experiments do (and do not) demonstrate.

Economists and biologists have proposed a distinction between two mechanisms--"strong" and "weak" reciprocity--that may explain the evolution of human sociality. Weak reciprocity theorists emphasize the benefits of long-term cooperation and the use of low-cost strategies to deter free-riders. Strong reciprocity theorists, in contrast, claim that cooperation in social dilemma games can be sustained by costly punishment mechanisms, even in one-shot and finitely repeated games.