5. And this unity we ought firmly to hold and assert, especially those of us that are bishops who preside in the Church, that we may also prove the episcopate itself to be one and undivided.18 [i.e., the universal episcopate is the chair of Peter.] Let no one deceive the brotherhood by a falsehood: let no one corrupt the truth of the faith by perfidious prevarication. The episcopate is one, each part of which is held by each one for the whole.19 [This maxim is the essence of the treatise; i.e., “Ecclesia in Episcopo.” Compare p. 333, note 9, supra.] The Church also is one, which is spread abroad far and wide into a multitude by an increase of fruitfulness. As there are many rays of the sun, but one light; and many branches of a tree, but one strength based in its tenacious root; and since from one spring flow many streams, although the multiplicity seems diffused in the liberality of an overflowing abundance, yet the unity is still preserved in the source. Separate a ray of the sun from its body of light, its unity does not allow a division of light; break a branch from a tree,—when broken, it will not be able to bud; cut off the stream from its fountain, and that which is cut off dries up. Thus also the Church, shone over with the light of the Lord, sheds forth her rays over the whole world, yet it is one light which is everywhere diffused, nor is the unity of the body separated. Her fruitful abundance spreads her branches over the whole world. She broadly expands her rivers, liberally flowing, yet her head is one, her source one; and she is one mother, plentiful in the results of fruitfulness: from her womb we are born, by her milk we are nourished, by her spirit we are animated.
V. Quam unitatem firmiter tenere et vindicare debemus, maxime episcopi, qui in Ecclesia praesidemus, ut episcopatum quoque ipsum unum atque indivisum probemus. Nemo fraternitatem mendacio fallat, nemo fidei veritatem perfida praevaricatione corrumpat. Episcopatus unus est, cujus a singulis in solidum pars tenetur. Ecclesia quoque una est, quae in multitudinem latius incremento foecunditatis extenditur. Quomodo solis multi radii, sed lumen unum; et rami arboris multi, sed robur unum tenaci 0501B radice fundatum ; et cum de fonte uno rivi plurimi 0502A defluunt, numerositas licet diffusa videatur exundantis copiae largitate, unitas tamen servatur in origine. Avelle radium solis a corpore, divisionem lucis unitas non capit: ab arbore frange ramum, fractus germinare non poterit: a fronte praecide rivum, praecisus arescit. Sic et Ecclesia Domini luce perfusa per orbem totum radios suos porrigit; unum tamen lumen est, quod ubique diffunditur, nec unitas corporis separatur. Ramos suos in universam terram copia ubertatis extendit, profluentes largiter rivos latius expandit ; unum tamen caput est et origo una, et una mater foecunditatis successibus copiosa. Illius foetu nascimur, illius lacte nutrimur, spiritu ejus animamur.