 Nonetheless, within the literature on friendship the notion of shared or joint activity is largely taken for granted: not much thought has been given to articulating clearly the sense in which friends share their activity. This is surprising and unfortunate, especially insofar as the understanding of the sense in which such activities are “shared” is closely related to the understanding of intimacy that is so central to any account of friendship; indeed, a clear account of the sort of shared activity characteristic of friendship may in turn shed light on the sort of intimacy it involves. This means in part that a particular theory of friendship might be criticized in terms of the way in which its account of the intimacy of friendship yields a poor account of the sense in which activity is shared. For example, one might think that we must distinguish between activity we engage in together in part out of my concern for someone I love, and activity we share insofar as we engage in it at least partly for the sake of sharing it; only the latter, it might be argued, is the sort of shared activity constitutive of the relationship of friendship as opposed to that constitutive merely of my concern for him (see Nozick 1989). Consequently, according to this line of thought, any account of the intimacy of friendship that fails to understand the sharing of interests in such a way as to make sense of this distinction ought to be rejected.