Maybe that's the incentive he needs.

Martha's pending due date was an incentive to Betsy.

The reward of title and degree and the consequent rise in the esteem of his fellows and himself was also a strong incentive; but the Mithraic faith itself was the greatest factor.

Horses are used to some extent for riding, but very little for carriage and draught purposes, consequently there has been no great incentive for their breeding.

If in his youth he had been prone to gambling, and before his marriage with Theodora had been somewhat lax in his morals, when he became a man he put away childish things; his married life was a shining example to his people and he was abstemious both in food and drink, holding that "excess in either was an incentive to the worst of crimes."