Quadragesimo Anno §14

¹⁴ However, in spite of such great agreement, there were some who were not a little disturbed; and so it happened that the teaching of Leo XIII, so noble and lofty and so utterly new to worldly ears, was held suspect by some, even among Catholics, and to certain ones it even gave offense. For it boldly attacked and overturned the idols of Liberalism, ignored long-standing prejudices, and was in advance of its time beyond all expectation, so that the slow of heart disdained to study this new social philosophy and the timid feared to scale so lofty a height. There were some also who stood, indeed, in awe at its splendor, but regarded it as a kind of imaginary ideal of perfection more desirable then attainable.