What was distinctive about this mini-symposium was that two reports among four were made from an evolutionary psychology viewpoint (Kai Hiraishi and Atsushi Naito). Thus the commentator first summarized orthodox juristic and psychological views on law and justice, and then gave an account of the background and the significance of the evolutionary psychology viewpoint. The comments in view of this are as follows. i）Along the course of evolution of homo sapience, who administered punishment for betrayal, how were the free-rider problems dealt with, and how was the punishment for betrayal systematized? ii）How should evolutionary psychology interpret the times when primitive trials arose in magical or religious rituals? How is it related to procedural justice that is the essence of trials? iii） What is the relation between the system of punishment for betrayal and a sense of injustice that was derived from the social brain homo sapience developed? Was there the estrangement between these two?
