Philosophical anthropology explains the human being in context of “nature”. This philosophical explanation is the foundation for understanding man as the source of personal activities in various human societes. Saint Thomas was a realist in his consideration of man, and so he had to consider man’s inclination to sin. During his 1979 pilgrimage to Poland, Pope John Paul II spoke in Warsaw, and said: “We cannot completely understand man without Christ”. His encyclical letter Fides et Ratio suggests that it is necessary to complete the investigations of the philosophical anthropology on real human activities that evoke activity.