Is there any special kind of sin which is directly opposed to charity as regards the external act which is called beneficence?
Yes, and the sin is called scandal (XLIII.).
What is scandal?
Scandal is that sin which through some word or deed offers to another an occasion of sinning; or the fact of taking occasion to sin because of what is said or done by another: in the first instance one gives scandal; in the second, one is scandalized (XLIII. 1).
Is it only weak souls that are scandalized?
Yes, that is those that are not as yet proof against evil; although many sensitive souls cannot help but be painfully affected when they see or hear something that is bad (XLIII. 5).
Are good and virtuous souls incapable of giving scandal?
Yes, because in the first place they never do or say anything bad that could really scandalize; if perchance scandal is ever given to others, this is due to the malice of the latter only (XLIII. 6).
May it not sometimes happen that virtuous souls are under an obligation to forego certain things lest weaker souls be scandalized?
Yes, provided of course it is not a question of things necessary for salvation (XLIII. 7).
Is one ever bound to forego some good thing in order that the wicked may not be scandalized?
No (XLIII. 7, 8).
Next - The Catechism of the Summa - SECOND SECTION - A DETAILED SURVEY OF MAN'S RETURN TO GOD - XI. OF THE PRECEPTS RELATING TO CHARITY