Abstract The claim that, in some nontrivial sense, nursing can be identified with caring has prompted a search for the philosophical foundations of care in the nursing literature. Although the ethics of care was initially associated with Gilligan's ‘different voice’, there has more recently been an attempt – led principally by Benner – to displace the gender perspective with a Heideggerian one, even if Kant is the figure to whom both Gilligan and Benner appear most irretrievably opposed. This paper represents the first half of a double-edged project: initially, to point out that Heidegger explicitly disowns any ethical implications for his ontological thinking, and to argue that no ethical theory (including an ethics of care) can be derived from Being and Time; and then to argue that Kant's categorical imperative is not only compatible with the ethics of care but actively entails it. In this, Heideggerian, part of the argument, I consider three attempts to wrest an ethics from Being and Time– those of Benner, Olafson and Guignon – suggesting that, for different reasons, they all fail. Benner systematically confuses the ontological with the ontic, not recognizing that care, concern and solicitude have ‘deficient’ modes as well as positive ones, and that Heidegger's ontology retrieves the possibility of an ethics-in-general without at any point implying an ethics-in-particular (whether of care or justice). Olafson does recognize this, and to that extent admits his failure, but his efforts to amplify Heidegger's thought in such a way as to generate an ethical theory involve both the importing of Kantian premises, and an appeal to some rather doubtful empirical observations. Guignon resorts to Heidegger's discussion of authenticity, and the idea that authentic Dasein ‘may choose its hero’, suggesting a morally reassuring list of heroes who might fit the bill. However, there is nothing in Heidegger's account of this choice that justifies his confidence, and I conclude by proposing that we should take Heidegger at his word when he says that ontology has ‘no result, no effect’.