Delectatio operationem perficit quia operatio causat delectationem sicut causa efficiens; delectatio autem perficit operationem per modum finis.
Pleasure perfects operation because operation is the efficient cause of pleasure, while pleasure perfects operation by way of final cause.
Delectatio perficit operationem inquantum scilicet super hoc bonum quod est operatio, supervenit aliud bonum quod est delectatio, quae importat quietationem appetitus in bono praesupposito.
Pleasure perfects operation inasmuch as to this good, which is operation, there is added another good, which is pleasure, denoting the repose of the appetite in a good that is presupposed.
Perficit delectatio operationem, inquantum scilicet agens, quia delectatur in sua actione, vehementius attendit ad ipsam, et diligentius eam operatur.
Pleasure perfects operation inasmuch as the agent, through taking pleasure in his action, is more eagerly intent on it, and carries it out with greater care.
Delectationes adaugent proprias operationes, et impediunt extraneas.
Pleasures increase their appropriate activities, and hinder those that are not appropriate.
Delectatio autem quae consequitur actum rationis, fortificat rationis usum.
Pleasure that arises from the act of reason, strengthens the use of reason.