http://www.princeton.edu/~ppettit/papers/2006/Joint%20Actions%20and%20Group%20Agents.pdf Pettit, P & Schweikard, D. (2006) "Joint Acitons and Group Agents" Philosophy of social Science 36 1 pp. 18-39 推論のジレンマ(discursive dilemma) と呼…