The existence of a Divine Being, and His demonstrability, has always been one of the most complex and interesting topic in the history of philosophy: within this context, the so-called “ontological arguments” has been a particular debated and controversial point. For this reason, there is a rising necessity to achieve an Observatory dedicated to Natural Theology in which it can be studied the topic of the Quaestio Dei from different perspectives, bringing to light not only the most common and classic positions, but even all the others speculative traditions usually less known. Rosmini retained that this problem is a central point in every philosophy, and especially in every authentic Metaphysical position. Therefore, a special attention will be dedicated to the “ontological arguments” or “a-priori proofs”: the philosophical debate about this issue has always been intense and stimulating, for abundance and variety of positions. For this reason, it appears extremely useful to provide to the scholars an instrument that can be a point of reference on this topic, complete and constantly updated, configured as an International Observatory on the state of the studies. Aside to an accurate historical survey, the Observatory will have primarily a theoretical approach, studying in particular the theoretical gains obtained in the context of Analytic Philosophy, privileging the most recently developments, from the half of XX century until the present day.