1 On the Unity of the Trinity’s External Works: Archaeology and Grammar Tyler R. Wittman [Published in IJST 20.3 (2018)] Abstract: The rule that opera Trinitatis ad extra indivisa sunt, servato ordine et discrimine personarum is best understood when its two clauses are read together as mutually informative. Read thus, and grasped according to its principles and grammar, the rule articulates two things: the pure benefit of God’s activity terminating in time, and the intimate yet unconfused relation between theology and economy. I: Introduction God’s simplicity requires that God is indivisibly ‘constant to himself’ in all the fullness of his being and activity as Father, Son, and Holy Spirit. 1 Because God’s fullness of life is a simple unity, an irreducible whole, God is indivisible in being and therefore in activity. Hence the doctrine that the Trinity’s external works are indivisible (opera trinitatis ad extra indivisa sunt). Though often invoked, this rule remains vulnerable to easy distortion when separated from the second clause of its more extended form: the order and distinction of the persons being preserved (servato ordine et discrimine personarum). 2 For example, one dominant concern about the rule is that it dulls the revelatory force of God’s external acts because it ‘tends to blur any real distinctions among the divine persons and thereby formalizes in Latin theology the breach between oikonomia and theologia’. 3 Some such unease about the rule’s ability to facilitate an adequate coordination of 1 Bernard of Clairvaux, De consideratione V.vii.16, in Bernard of Clairvaux: Selected Writings, trans. G.R. Evans (New York: Paulist Press, 1987). 2 Heinrich Schmid, Die Dogmatik der Evangelisch-lutherischen Kirche, 4 th ed. (Frankfurt: Heyder & Zimmer, 1858), pp. 104-5. See Carl Beckwith’s historical account of this addendum in The Holy Trinity, vol. 3 of Confessional Lutheran Dogmatics, ed. Gifford A. Grobien (Ft Wayne: The Luther Academy, 2016), pp. 310-35. On the patristic background to the rule more generally, see Michel René Barnes, ‘One Nature, One Power: Consensus Doctrine in Pro-Nicene Polemic’, in Elizabeth A. Livingstone, ed., Studia Patristica vol. 29 (Leuven: Peeters, 1997), pp. 205-223. 3 Catherine Mowry LaCugna, God For Us: The Trinity and Christian Life (New York: HarperCollins, 1991), p. 99.