Catechism of the Catholic Church §1931 — excerpt
Respect for the human person proceeds by way of respect for the principle that "everyone should look upon his neighbor (without any exception) as 'another self,' above all bearing in mind his life and the means necessary for living it with dignity."
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 27 # 1