Catechism of the Catholic Church §1754 — excerpt
The circumstances, including the consequences, are secondary elements of a moral act. They contribute to increasing or diminishing the moral goodness or evil of human acts (for example, the amount of a theft).
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.