See Petrus de Palude, book 4, distinction 15, question 3, conclusion 4, about the gain arising from acting. Also Angelus in his Summa under restitutio, part 1, section 6.
4. Fourthly, that a work which brings public advantage, either spiritual or temporal, is not necessarily unlawful because some people are thereby provoked to sin.
Otherwise it would be unlawful to manufacture arms or to make war.
On these premises I base the following propositions:
1. The lottery is not in itself unlawful.
Proof. It is not prohibited by any law, divine, human, or natural: divine, because it is not forbidden in Scripture; human, because there is no law against it as there is against hazard or dicing; natural, because it is not excluded as (a) coming by good fortune, (b) provoking others to sin, (c) vain and useless.
a and b are proved by premiss 1 and 4. c is proved because we are supposing that the lottery is undertaken in order that the city of Bruges may make a profit with which to pay off some of its municipal debt, or be lightened of some of its common burdens, so that its citizens may be free to journey whither they please. (That this last refers among other things to pilgrimage, may be inferred from a reference to the Canon Law on the undertaking of journeys, chapter on Sacred Churches.)
2. The lottery is not prohibited by the human laws forbidding hazard and dice.
Proof. The laws prohibiting these do not forbid the lottery, nor can it be included under them by parity of reasoning. For hazard is not forbidden because it depends on chance, or else all gaming would be forbidden; and it is not forbidden to play for small stakes or on the occasion of a party. But it (hazard) is forbidden because, as Petrus de Palude says in book 4, distinction 15, question 3, article 5, the person who loses is wont to blaspheme; and also because men are tempted to lose more than they can afford.'
We need not follow the argument in detail, but the fourth proposition is interesting, 'That there is an injustice in the lotteries as practised by some cities, in that the creditors of the city are compelled against their will to take part in the lottery, and so probably make a loss, for fear of not recovering the money owed to them'. After six propositions come two contrary arguments, which are refuted by five and two considerations; and then there is a brief summing up.