Point III. On Wagering

I. Notion. Wagering is a contract by which two or more persons, contending about the truth of some thing or about an event, promise a prize to him who will be shown to have attained the truth.

II. Condition required for the justice of wagering is that equality be preserved among those wagering as regards hope of the prize and danger of loss. Hence the truth of the thing or event must be uncertain to each. One who is certain of that about which there is contention cannot wager (St. Alphonsus, Homo Apostolicus, tr. 10, n. 214).

But what if one who is certain of the truth or event warns the other about his certainty, and the other nevertheless wishes to wager? With St. Alphonsus against many, it seems that it must be said that the wagering is unjust, because the prize is unjust in itself, and the other is not per se judged to yield his right to a just prize (St. Alphonsus, III, 879; Homo Apostolicus, tr. 10, n. 214). Make exception if the other sufficiently manifests that he consents to the prize, whatever it may be.