Catechism of the Catholic Church §356 — excerpt
Of all visible creatures only man is "able to know and love his creator". He is "the only creature on earth that God has willed for himself", and he alone is called to share, by knowledge and love, in God's own life.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: GS 12 # 3 · GS 24 # 3 · St. Catherine of Siena, Dialogue IV, 13 "On Divine Providence": LH, Sunday, week 19, OR