WE gather from the letter itself that Constantius, to whom it is addressed was a newly appointed Bishop, but of what see does not appear. In § 27 S. Ambrose commends to his care the see of Forum Cornelii, which was vacant at the time, as being in his neighbourhood. The grounds on which the Benedictine Editors fix the date seem rather vague. Its interest however is not historical: it is simply hortatory, urging on Constantius the fulfilment of the duties of his new office, and setting before him the chief subjects to which his preaching should be addressed. From S. Ambrose calling him ‘my son’ (§ 27) it would seem that he was either one of his own clergy, or had been in some way under his guidance. It is interesting as shewing how a great Bishop of that age dwelt upon the relations of the Episcopate, not merely to the Clergy under him as their superior, but to the laity of his diocese as their chief teacher. AMBROSE TO CONSTANTIUS. Sidenote: Ps. xxiv. 2. 1. YOU have undertaken the office of a Bishop, and now, seated in the stern of the Church, you are steering it in the teeth of the waves. Hold fast the rudder of faith, that you may not be shaken by the heavy storms of this world. The sea indeed is vast and deep, but fear not, _for He hath founded it upon the seas, and prepared it upon the floods_. Rightly then the Church of the Lord, amid all the seas of the world, stands immoveable, built as it were, upon the Apostolic rock; and her foundation remains unshaken by all the force of the raging surge. The waves lash but do not shake it; and although this world’s elements often break against it with a mighty sound, still it offers a secure harbour of safety to receive the distressed. Sidenote: Ps. xciii. 4. Sidenote: S. John vii. 38. Sidenote: Isa. lxvi. 12. Sidenote: Ps. xlvi. 4. 2. Yet although it is tossed on the sea, it rides upon the floods; and perhaps chiefly on those floods of which it is said, _The floods have lift up their voice_. For there are _rivers_, which _shall flow out of his belly_, who has received to drink from Christ, and partaken of the Spirit of God. These rivers then, when they overflow with spiritual grace, lift up their voice. There is a river too, which runs down upon His saints like a torrent. And there are _the rivers of the flood_, which _make glad_ the peaceful and tranquil soul. He that receives, as did John the Evangelist, as did Peter and Paul, the fulness of this stream, lifts up his voice; and like as the Apostles loudly heralded forth to the farthest limits of the globe the Evangelic message, so he also begins to preach the Lord Jesus. Receive to drink therefore of Christ, that your sound may also go forth. Sidenote: Prov. xvi. 24.