Being and Time describes his project in the following way: "our aim in the following treatise is to work out the question of the sense of "being" and to do so concretely." Heidegger claims that traditional ontology has prejudicially overlooked this question, dismissing it on the basis that being is the most universal and emptiest concept, that is indefinable or obvious. Instead Heidegger proposes to understand being itself, as distinguished from any specific entities (beings). "'Being' is not something like a being." Being, Heidegger claims, is "what determines beings as beings, that in terms of which beings are already understood." Heidegger is seeking
Being eventually entail the shortening and lengthening of time as well which has never been observed. This logical objection, which was made on Aristotle's argumentation, could not be answered in the ancient times or medieval age, but now it does not sound contradictory to the real nature of Time (as addressed in relativity theory), so by a reverse argument, a philosopher may indeed deduce that everything is changing (moving) even in the deepest core of Being. Although innovated in the late medieval period, Thomism was dogmatized in the Renaissance. From roughly 1277 to 1567, it dominated the philosophic landscape. The rationalist