12 A work of such importance requires from the directors of souls a more than ordinary prudence and an indefatigable care; and it is our desire that this office, which we wish should not be lacking in any seminary, should be confided to an ecclesiastic of great experience in the ways of Christian perfection. It can never be sufficiently recommended to him to found and cultivate in his pupils that piety which is for all, but especially for the clergy, of the greatest fruitfulness and inestimable utility.(15) Therefore, he will be solicitous to warn them against a pernicious snare not unfrequent among young men - that of giving themselves so entirely and with such ardor to their studies as to neglect their advancement in the science of the saints. The deeper root piety has taken in clerics' souls, so much the more will they be filled with that strong spirit of sacrifice which is altogether necessary to work for the divine glory in the salvation of souls. Thanks be to God, there are not lacking among the Italian clergy priests who give noble proof of what a minister of God, penetrated with that spirit, can do; wonderful, indeed, is the generosity of many who to spread the Kingdom of Jesus Christ voluntarily hasten to distant countries, there to encounter fatigues, privations and hardships of every kind and even martyrdom itself.
Source: Fin dal Principio (Vatican.va)