 One way to capture degrees of moral status is to vary the strength of the reasons outlined in section 2 (and hence also the degree of wrongness involved in acting against these reasons – see DeGrazia 2008). For example, while there is a very stringent moral presumption against killing an unimpaired adult human being, there might be only strong but non-stringent reasons not to kill a dog, and very weak reasons not to kill a fish. The weaker the reason not to kill is, the broader the set of circumstances are that can override this reason. In addition, it will silence fewer, if any, conflicting considerations. The other categories of reasons would be handled similarly: when the benefit to be received, the cost of providing that benefit, and other similar factors are on a par, there is a strong reason to aid an unimpaired adult human being, but only some reason to aid a dog, and very little reason to aid a fish, and so on.