In this article I present a special contribution to universalism by the Cracow Circle (Bocheński, Drewnowski, Salamucha). Presented thinkers were scientists, philosophers and theologians, and tried to combine these disciplines in their works. They took standards of rationality from logic and other sciences, and applied them to Christian philosophy and theology. This kind of rationality can be considered universal and when we use this rationality in dialogue between religion and other worldviews, the dialogue has a chance to be really universal.