This comparative essay about two kinds of interpersonal-centric humanism is dedicated to the memory of professor Janusz Kuczynski and his conception of dialogical universalism as a metaphilosophy, and shows Immanuel Kant’s thought as a ceaseless source of inspiration for all anti-conservatives and universalists. Kant’s philosophy gave man an unforgettable sense of freedom, because it not only posed the imperative of building a pan-human community of all rational beings, but also revealed the above-natural sense of the human species’ imposition of purposefulness upon itself, and the realisation of this purposefulness in the form of a republican federation of free states dedicated to co-creating eternal peace. Kantian ethics did not reach beyond the obligations people had towards one another, hence it was functionally anthropological and uninfluenced by religion, which re-situated philosophy with regard to scientific cognition and religious experience, giving rise to a metaphysics of anthropological responsibility for the condition of the spiritual freedom this ethic propounded. Kant revealed the existence of a metaphysical difference in the sphere of being—between the determinism of nature and the moral kingdom of freedom—without direct reference to the transcendental source of these two essentially different worlds. Kant was the first to set morality rooted in the autonomy and unanimous will of all rational beings—or true humanity—against legal and religious legalism. Kant laid weight on the processual character of man’s self-education to social life through the sense of commitment to self-improvement for the benefit of the solidary co-existence of all rational beings that he developed in himself as a rational being. Thus created freedom is founded on the selflesness of goodness and represents a new quality of being that only manifests itself and evolves in community, interpersonalcentrically. It is a universalistic approach capable of gradually neutralising the human inclination towards radical evil. My attempt to compare these two interpersonalcentric humanism conceptions aims to add some substance to this very delicateelement in Kuczynski’s universalism as a metaphilosophy construct. Keywords: interpersonalcentric humanism, philosophy of metaphysical responsibility, metaphysical difference, Immanuel Kant, universalism as a metaphilosophy, Kuczynski, spiritual selflessness, homo creator, metaphysics of morals vs. legal/ religious legalism, philosophy of dialogue.