Section — Wouters, Manual of Moral Theology

Scholion. On the Contract of Rendering Certain Services

919.

As regards agreements about certain services to be rendered, it is sufficient to note these things: one who renders to someone a service already owed to another - for example, one who leads several persons at the same time to some place, or brings a message to several persons at the same time - can ask payment from each. For since the work rendered here and now is ordered wholly and entirely to each one, and is useful to each, it does not seem unjust to ask compensation from each one (St. Alphonsus, III, 862). Nevertheless he cannot demand the price twice for that which he himself bought only once, for example for a meal, for a carriage, because such a price is demanded after the manner of restoring damage, and therefore ought not to exceed the damage itself.