42. Lately when fulfilling the apostolic duty of putting the Catholics of North America on their guard against innovations, tending, among other things, to substitute for the principles of perfection consecrated by the teaching of doctors and the practice of saints moral maxims and rules of life more or less impregnated with that naturalism which nowadays endeavors to penetrate everywhere, we proclaimed aloud that far from repudiating and rejecting "en bloc" the progress accomplished in the present epoch, we were only too anxious to welcome all that goes to augment the patrimony of science or to give greater extension to public prosperity. But we took care to add that this progress could be of efficacious service to the good cause only when harmonized with the authority of the Church.³³