Pope Pius XI
Quadragesimo Anno §7
Quadragesimo Anno: On Reconstruction of the Social Order
7 In such a sharp conflict of mind, therefore, while the question at issue was being argued this way and that, nor always with calmness, all eyes as often before turned to the Chair of Peter, to that sacred depository of all truth whence words of salvation pour forth to all the world. And to the feet of Christ's Vicar on earth were flocking in unaccustomed numbers, men well versed in social questions, employers, and workers themselves, begging him with one voice to point out, finally, the safe road to them.
Source: Quadragesimo Anno (Vatican.va)