35 Venerable Brethren, the time is drawing near for the Second General Council of the Vatican. Surrounding the Roman Pontiff and in close communion with him, you, the Bishops, will present to the world a wonderful spectacle of Catholic unity. Meanwhile We, for Our part, will seek to give instruction and comfort by briefly recalling to mind St. Leo's high ideals regarding the Church's unity. Our intention in so doing is indeed to honor the memory of a most wise Pope, but at the same time to give the faithful profitable food for thought on the eve of this great event.
Source: Aeterna Dei Sapientia (Vatican.va)