If I sought only my individual good, I would never engage in an exchange. I would seek the thing I desire, but I would never seek to satisfy the desire of someone else to obtain it. To seek to satisfy another in an exchange is precisely to move beyond my own good, that is to make the others good COMMON to him and me. My desire for my own good indeed is the impetus for me to embrace the good of another, but it is precisely in this that the good of the other becomes my good and therefore a common good. Exchange and mutual cooperation can only be understood within the framework of shared or common goods.
How many times is “mutual benefit” used as the reason for an exchange? What is the mean of “mutual” other than something “shared” or “common” and what is a “benefit” other than a “good” of some kind? It seems that “common good” must have some connotation that is repellant whereas “mutual benefit” is pleasing to the ears. In either case, an exchange aims at mutual benefit and indeed the whole of society aims at mutual benefit. The “collectivist fallacy” is not a fallacious, but we might talk about the “individualistic fallacy,” but such language of “fallacy” seems only to disrupt discussion rather than propose an argument.
As it stands, the error of Mises et al. is a matter of contradiction. Individuals do act for their own good, but in acting for their own good they also make the good of others their own good, because they realize the good of cooperation and peace. There is no contradiction between individuals seeking their own good and the common good of the whole of society. Rather attempting to understand the most basic exchange while simultaneously denying the “common good” and making ceaseless reference to the “mutual benefit” of the individuals is a contradiction.