The aim of the paper is to unify the natural sciences with the human sciences.Unification rests on the foundation of the original thesis at the center of this paper and which concerns the Ontology of Being. In reality, in the absence of an Ontology of Being, every science, insofar as it concerns reality, is up in the air, unaware of its foundation.The method of investigation consists in testing its explanatory and clarifying power by addressing the fundamental questions of both areas, in particular physics, philosophy and the mind-body problem.A true Ontology of Being, in fact, must be able to bring all the sciences back to itself, and therefore to clarify their structure as they branch out, explaining them in their being identical and in their being different.The result is that the proposed ontological thesis, which derives from the synergy of the acquired results of both sciences, reacts on them, purifying their foundations and therefore spanning the way to their safer advancement. Indeed, the natural and human sciences, each in their own domains and with their own methods, apparently so distant, concern the two opposite moments of the same being. In other words, they are complementary to each other, as the act is to the potency, as external is to internal, as dead is to life, as the consciousness is to the soul, as electricity is to gravitation, as each makes no sense without the other but needs the other and is completed in the other.The promised science is the overcoming in the synthesis of these two opposite moments.