Raw reference: nos. 36-38, 46-47
CCC 36
"Our holy mother, the Church,
"Our holy mother, the Church, holds and teaches that God, the first principle and last end of all things, can be known with certainty from the created world by the natural light of human reason." [Vatican Council I, Dei Filius 2: DS 3004 cf. 3026; Vatican Council II, Dei Verbum 6.] Without this capacity, man would not be able to welcome God's revelation. Man has this capacity because he is created "in the image of God". [Cf. Gen 1:27]
CCC 37
In the historical conditions
In the historical conditions in which he finds himself, however, man experiences many difficulties in coming to know God by the light of reason alone:
CCC 38
This is why man stands in
This is why man stands in need of being enlightened by God's revelation, not only about those things that exceed his understanding, but also "about those religious and moral truths which of themselves are not beyond the grasp of human reason, so that even in the present condition of the human race, they can be known by all men with ease, with firm certainty and with no admixture of error". [Pius XII, Humani generis 561: DS 3876; cf. Dei Filius 2: DS 3005; DV 6; St. Thomas Aquinas, S Th I, I, I.]
CCC 46
When he listens to the
When he listens to the message of creation and to the voice of conscience, man can arrive at certainty about the existence of God, the cause and the end of everything.
CCC 47
The Church teaches that the
The Church teaches that the one true God, our Creator and Lord, can be known with certainty from his works, by the natural light of human reason (cf. Vatican Council I, can. 2 # 1: DS 3026),