Currently, there are three approaches we can use to discuss what is still labelled as disability: medical, social and biopsychosocial (the latter being an attempt to integrate and ameliorate the conflict between the first two). The Foro de Vida Independiente (FVI) [Forum for Independent Living], and the authors and activists who help to expand their proposals, celebrate the significant progress achieved by the biopsychosocial approach, but remain dissatisfied with it and propose a new model called functional diversity, a hermeneutic version of the social approach. This article attempts to identify the problems that the model of functional diversity poses to applied ethics, focussing in particular on two issues. The first is: if we now consider that an impairment should be interpreted only as diversity, What arguments would we have against parental decisions not to correct a physical, intellectual or developmental impairment in their children even though such an intervention were effective, reasonable and safe? And what arguments would we have in order to avoid those parents causing them an impairment? The second problem is: How can we justify the need for affirmative action (more resources and attention, more medical and technological research for people with functional diversity) or even justify providing support, if we consider that their way of functioning is not better or worse than any other?