This is a very interesting and well-elaborated theoretical paper on the relationship between intertemporal utility and intertemporal rationality when rationality is not necessarily related to the stationarity of the utility function. This relationship is studied on the basis of an additive utility functional that generalizes as much as possible the functions having been used thus far. From this point of view, the paper offers a critical review of the existing literature on the subject, while the mathematical novelty of the proposed general additive utility can become a solid basis for future work on it.