This paper distinguishes two conceptions of collectivity, each of which tracks the targets of classification according to their aetiology. Collectivities falling under the first conception are founded on (more-or-less) explicit negotiations amongst the members who are known to one another personally. Collectivities falling under the second (philosophically neglected) conception are founded – at least initially – purely upon a shared conception of "we", very often in the absence of prior acquaintance and personal interaction. The paper argues that neglect of collectivities of the second kind renders certain social phenomena (for example, sense of place and certain kinds of conflicted loyalty) inexplicable or invisible. And the paper also stresses that a conception referring to the second kind of collectivity will put us in position to revitalize a variety of important questions, including: Which conception of collectivity best serves the needs of a theory of justice? The paper will contrast the distinction between these two conceptions with the classical Gemeinschaft/Gesellschaft distinction, as well as with the more recent attempts to articulate differences between groups according to membership-structuring norms.