CCC 1753
Life in Christ›SECTION ONE MAN'S VOCATION LIFE IN THE SPIRIT›CHAPTER ONE THE DIGNITY OF THE HUMAN PERSON›I. The Sources of Morality
A good intention (for example, that of helping one's neighbor) does not make behavior that is intrinsically disordered, such as lying and calumny, good or just. the end does not justify the means. Thus the condemnation of an innocent person cannot be justified as a legitimate means of saving the nation. On the other hand, an added bad intention (such as vainglory) makes an act evil that, in and of itself, can be good (such as almsgiving).