[citation needed] Bob Corbett[5][6] argues that Singer's definition of "moral obligation" is too broad,[7] and objects to the simplistic extremity of Singer's concepts of "Absolute Poverty" (anything below survival threshold) and "Absolute Luxury" (anything above survival threshold).
[8] He argues that Singer's definition of what is possible for an individual, while technically adhering to the letter, violates the spirit of the Kantian principle that "ought" implies "can".
[citation needed] Corbett further argues that his own definition of circumstances that meet the criteria of a "moral obligation" exists only in extreme proximity: for example a car crash directly in the presence of a medical professional.
For Pettit, the fact that I have done my fair share is enough of a justification for having let the child die; thus, I cannot reasonably be denounced for having acted in this way.
[citation needed] Kagan further argues that Nagel's argument may justify acting to promote our own projects but it does not appear to account for the fact that we are free to sacrifice our own interests if we choose to do so.
Kagan claims that Nagel's argument implies that such a sacrifice must always be irrational when one has conflicting agent-relative reasons.