In political and social philosophy, the philosophy of culture, and in the field of cognitive sciences—supported by the neurosciences, biology and psychology—the same metaphysical aim may today be observed, that is an aspiration to discover, still unattainable, the border between Appearance and Reality. In this context, how can we form various models of ethics, theories of laws or political systems if we are unable to give “clear and distinct” criteria of what is real, and thus what is true?