 Informed by philosophical reflection on the elements of the grateful response  (section 3),  philosophers have developed various accounts of gratitude that conceptualize and classify it as a certain kind of phenomenon. This section critically summarizes four prominent ways philosophers have tried to conceptualize and classify gratitude. All of these accounts highlight important features of gratitude and its relationship to other concepts, like the vices of ingratitude or pride, or the negative reactive attitude of resentment. Each conceptualization, however, does an imperfect job of accounting for all the elements of the grateful response (though not all of them purport to be comprehensive conceptualizations that account for every element of the grateful response).