 The constitutivist strategy appears to be particularly problematic for the varieties of Kantian constructivism that derive moral obligations from structural features of rational agency. Many contend that understood as a constitutive standard the categorical imperative is not rich enough to identify moral obligations (Cohen 1996; Bratman 1998; Gibbard 1999: 149, 152–153; Fitzpatrick 2005). Some constructivists offer similar grounds for rejecting Kantian constructivism about reasons (see  sections 3,  4,  5.1).  In fact, most Kantian constructivists deny that moral obligations can be derived from universal features of bare rationality alone and also deny that appeal to constitutive norms of rationality is sufficient to provide a complete system of moral duties (Bagnoli forthcoming).