  Another version of the criticism that cosmopolitanism is impossible targets the psychological assumptions of moral cosmopolitanism. Here it is said that human beings must have stronger attachments toward members of their own state or nation, and that attempts to disperse attachments to fellow-citizens in order to honor a moral community with human beings as such will undermine our psychological functioning. If this is a viability claim and not simply a desirability claim, then it must be supposed that moral cosmopolitanism would literally leave large numbers of people unable to function. So it is claimed that people need a particular sense of national identity in order to be agents, and that a particular sense of national identity requires attachment to particular others perceived to have a similar identity. But this does not seem to be true as an empirical generalization. The cosmopolitan does not need to deny that some people do happen to have the need for national allegiance, so long as it is true that not all people do; and insofar as some people do, the strict cosmopolitan will say that perhaps it does not need to be that way and that cosmopolitan education might lead to a different result. The historical record gives even the strict cosmopolitan some cause for cheer, as human psychology and the forms of political organization have proven to be quite plastic. 