Chapter 21: On the most holy Trinity; from essence to subsistence
CHAPTER TWENTY-ONE. On the most holy Trinity.
Thus far we have treated of GOD as to existence and essence: next is that we consider Him according to His subsistence, according to which the one and highest God is the eternal Father, the Son begotten from eternity from the Father, and the Holy Spirit proceeding from both — undivided TRINITY and unmixed UNITY.
This mystery was handed down somewhat obscurely by the ancient Church of the Jews in the Old Testament, but more clearly and illustriously explained by the LOGOS Himself, the second person of the Trinity, after He assumed flesh, in the New Testament, in which the interpretation of the Old is contained, and this secret is more expressly set forth and more frequently inculcated.
Latin
CAPUT VIGESIMUM PRIMUM, De sacrosancta Trinitate. Hactenus egimus de DEO, quantum ad exsistentiam et essentiam: proximum est ut eum consideremus secundum subsistentiam suam, secundum quam Deus unus et summus est Pater aeternus, Filius ab aeterno a Patre genitus et Spiritus Sanctus procedens ab utroque, indivisa TRINITAS et impermixta UNITAS. Mysterium hoc subobscure antiqua Judaeorum Ecclesia in veteri Testamento traditum fuit, clarius vero et illustrius ab ipso LOGO, secunda Trinitatis persona, post assumptam a se carnem explanatum in N.T., in quo veteris interpretatio comprehenditur, et arcanum hoc disertius exprimitur, frequentiusque inculcatur.