Thesis.
SECTION III: ON THE SIMPLICITY OF THE DIVINE ESSENCE
Thesis.
§ 129. The essence of God is utterly simple, free of all composition, mixture, and division, and, therefore, of all accidents. We prove this: (1) From the removal of all types of composition. There are seven modes of composition: first, of quantitative parts, as body. Second, of material and form, as an essential composite. Third, of genus and difference, as any species. Fourth, of subject and accident, as any created substance. Fifth, of actuality and potentiality. Sixth, of individual substance [suppositum] and nature. Seventh, of being [esse] and essence [essentia]. However, God is composite in none of these ways.
(2) From God’s infinity. (3) From God’s perfection. (4) From God’s eternity. Everything composite has a beginning, for the components cannot exist after the composition but do exist prior to it. The Scholastics say: “In God there cannot be two extreme substantial components that nevertheless are distinguished in actuality in the nature of the thing. For those things that are distinguished from each other in the nature of a thing cannot be joined together with each other nor coalesce except through the act of some efficient cause that always comes earlier.”
(5) From the identity of the attributes with the divine essence. (6) From the immutability of God. (See Augustine, De Trinit., bk. 5, 16. See also our commonplace [1610 Loci Theologici, locus 3 (On the Nature of God)], §§ 80–82.)
Justin writes: “God is not like a created nature so that what He is and what He has would be understood as composite, like a created nature; instead, He possesses a nature. Thus we must understand Him as possessing what He is and what He has beyond composition” (QQ. et resp. ad orthod., q. 144, p. 379). Origen, 
, bk. 1, c. 1, vol. 1, p. 668: “We should not think that God, who is the beginning of all things, is composite, lest by chance principles earlier than Him be found. There are elements of which everything, whatever is said to be composite, is composed.” Rufinus, Expos. symb.: “When you hear ‘God,’ understand a substance without beginning, without end, simple, without any mixture, invisible, incorporeal, ineffable, inestimable, in whom there is nothing added, nothing created, without source; for it is He who is the Creator of all things.” The Damascene, De orth. fid., bk. 1: “The divinity is simple and uncompounded.”
§ 130. Furthermore, God is simple in this manner: (1) That He is absolutely simple. Angels and souls are said to be simple in a comparative sense because they are not composite like bodies, but God is said to be simple in the absolute sense because He admits no composition. The more unified the power, the stronger it is; the more unified it is, the more simple it is. Therefore the stronger or more powerful it is, the more simple it is. Because the essence of God is omnipotent, it is utterly simple.
(2) Not only that He is free of all composition in Himself and in His essence (because in Him there really is no distinction between what He is and that by which He is, between Him who has and what He has) but also that He cannot come into a compounding with anything. For whatever comes into a compounding of something does not act first and of itself.23 For a hand does not act, but a man acts through his hand. Therefore if God were the form of a body, He would not be a cause that acts first and of itself, and as a consequence He would not be the first cause. (Cf. Savonarola, De verit. fid., bk. 1, c. 7.) Only an incomplete being comes into compounding with another, because of its own nature it is suitable to compose with another incomplete being something more complete as both are compounded. But God is a complete and utterly perfect being.
Antithesis.
§ 131. The simplicity of God is undermined by: (I) Vorstius: “There appears to be some diversity in God, so that God’s living substance itself is one thing, while life or the power through which He lives is another” (Tract. de Deo, p. 247). Ibid., p. 209:
There are no commonly accepted axioms that are simply and in all ways true, that no diversity nor composition occurs in God; also that there is no accident at all in God, but that whatever is in God is God Himself. Are there not different persons in God? Are there not different relationships? Is the begetting of God the same thing as God Himself, or is His active begetting the same as His passive begetting? Or is acting the same thing as suffering [pati]? And if all these things are God Himself, how do they differ among themselves?
(Anyone will notice readily in what direction these ideas are headed, namely, to destroy the mystery of the Trinity as contradictory to the simplicity of the divine essence. But we shall speak about this object a little later.) On p. 210 he writes: “In God, essence (spiritual essence, the equivalent of “genus”) is like the material, and certainly the essential properties (the equivalent of “difference”) are like the form.” Ibid.: “Nothing prevents us from asserting generally [generatim] that one thing and another [aliud atque aliud] are in God or even that they are in the essence of God and that it is this way from eternity by the necessity of nature. We have various testimonies of Scripture that assert that one thing and another are in God, namely, subject and accident or agent and action, for example, when God swears by His soul (Jer. 51:14; Amos 6:8) and when a spirit is said to be in Him (1 Cor. 2:11).” Also: “The living subject is one thing and life is another, just as the one who has is one thing and what he has is another.”
Yet (1) one infers clumsily that the essence and attributes of the divine essence really are different in God simply because our mind conceives and considers them distinctly. (2) Difference differs really from genus because it is outside the essence of genus. But the essential properties of God do not differ really from God’s essence; they are not outside God’s essence nor are they accidents of His essence, as we pointed out in great detail in our commonplace [1610 Loci Theologici, locus 3 (On the Nature of God)], § 48. (3) God’s essence is categorically different [plusquam toto genere differt] than the essence of created things because the former is infinite, the latter, finite. Therefore when the divine attributes are predicated of the divine essence, it is not that the differences restrict the breadth of the genus but that they are predicated of the divine essence [as] really the same with it. (4) Living and life do not differ really in God because God does not live through some addition to His essence but has life in Himself (John 5:26) and is life itself. He lives of Himself and through Himself. (5) Vorstius contradicts himself. He says: “Whatever of goodness and perfection is in creatures, this entire thing is in God by the manner of simple form.” However, that simple form cannot be compounded, otherwise it would be neither simple nor accidental and otherwise God would not be substance. (6) One must distinguish a categorical accident [accidens praedicamentale] from an accident that can be predicated [accidens praedicabili]. There is no categorical accident in God but, because of His freedom of will in acting, some things are predicated about God accidentally and contingently, such as that He may destroy the world at this moment. It is one thing for something to be inherent in God accidentally, another for something to be said about God accidentally with an external predication. (See our De glor. Dei, disp. 5, thesis 13.)
(II) Some Calvinists who use improper language. Zanchi writes: “We can reverently and truly call the three persons the parts of God, namely, the essential parts.” Therefore it can be said “that God, or His divine essence, consists of those three things as His essential parts” (De trib. Elohim, bk. 2, c. 7, p. 529). Piscator says that the essence common to the three persons of the Trinity is “like a genus” and that the persons are “like species.” Augustine’s statement is pleasing to us: “The divine essence is predicated of the three persons not as a whole [is predicated] of its parts nor as a genus of its species nor as a species of its individuals but in another ineffable and incomprehensible way.” For a whole is not in one of its parts, a genus is not in one of its species, but the entire and undivided essence of God is in the Father, the entire and undivided essence is in the Son, the entire and undivided essence is in the Holy Spirit. (See our disputation De glor. Dei, loc. cit.) Some Calvinists, such as Sohn and Pezel, teach: “With reference to His person, the Word is not outside the assumed flesh; but because the essence of the Word nevertheless is infinite, in this respect the Word is outside the flesh in an infinite number of places.”
(III) The architects of the absolute decree [in the doctrines of providence and predestination]. Those who attribute contrary wills to God undermine the simplicity of the divine essence, for wherever there are contradictions of will, there is no room for the supreme and most perfect simplicity. But the architects of an absolute decree attribute contrary wills to God. Beza, par. 2, Resp. ad Coll., p. 173: “That which lies hidden in God at times disagrees with what He reveals; therefore the will of the sign24 or revealed will contradicts the other secret will.” Zanchi, De natura Dei, c. 2, p. 697: “Although when he sins man does what God wills by God’s secret and just will, nevertheless he cannot be excused when he acts contrary to that will of God on the basis of which he knows all things must be done.” Piscator (vol. 2, Loc. 12, p. 171) lists among the problems also this one: “Does God will some things by His revealed will that He does not will by His secret will?” Keckermann affirms this (Syst. theol., bk. 1, c. 7, p. 140) and sets His volition of good pleasure directly against His volition of the sign.
(IV) The Marcellians [Marcellini] who imagined a waxlike extension in God. Around the year of Christ 1140, the Arnoldists said that there is something in God, besides God, that is eternal. This same error was made by Peter Abelard, against whom Bernard worked, bk. 3, c. [5] of his Vita.
(V) Socinus: “Because Holy Writ does not testify anywhere that God’s essence is utterly simple and because to assert anything about God besides what has been expressed in Holy Writ should be considered dangerous, as much as we can, we abstain both from that and from other statements of the same sort, though they otherwise may appear to be utterly true and precise” (Defens. animadv., p. 44). And later: “… though concerning God’s essence, that it is utterly simple, we affirm nothing.”
Questions about the simplicity of the divine essence.
§ 132. (I) The question arises: Does the use of concrete language conflict with the simplicity of God? We respond. God is said to be not only life itself but also living, not only love and goodness itself but also good. Therefore one may use concrete language that nevertheless infers no composition in God as it does in creatures because life and goodness are predicated of God not accidentally but essentially. Thomas, [ST,] part 1, q. 3, art. 4: “Concerning simple things, we speak in the manner of composite things, from which we receive understanding. Therefore when we speak about God, we use concrete words to signify His subsistence, because in our experience, only composite things subsist, and we use abstract words to signify His simplicity. Therefore we say ‘deity’ or ‘life’ or something of this sort even of God, but we must relate these expressions to the diversity that exists in the comprehension of our intellect, not to some diversity of the thing itself.” In this way, when Christ says, “The Father has life in Himself” (John 5:26), He is not distinguishing the life of the Father from the Father’s essence, as an accident from its subject. Instead, He is accommodating Himself to our comprehension and establishing God as the unfailing and inexhaustible source of life. (See Ps. 36:[9].)
§ 133. (II) The question arises: Does it conflict with the simplicity of the divine essence to assert that God is the being of all beings, the life of all living things, etc.? We respond. Bernard, sermon 4 on the Song of Songs: “I certainly would have said that He is the God of all, not because they are what He is but because of Him and through Him and in Him are all things. He Himself, the maker of all things, is their being—but according to cause, not material.” Therefore God is called the essence of all created things, not by formation and composition but with respect to creation, preservation, control, and direction. This is not at all opposed to His utterly simple essence. Augustine refutes the opinion of those who believed that “God is the soul of the world, and the world is the body of God.” He says: “It will follow that whatever anyone steps on, he will step on a part of God and that a part of God is slain in the slaying of every animate thing” (De civ. Dei, bk. 4, c. 12).
§ 134. (III) The question arises: Does the trinity of persons militate against the simplicity of God? It seems this way to the Photinians. For this reason, they cry out that we are introducing a “three-formed, three-personed, and composite” God. Vorstius pours cold water on the Photinians, De Deo, p. 208: “There are at least three, if not more, things in God. It appears to be a contradiction, that anything truly exists that does not have a proper essence of its own.”
We respond. Justin answers: “God is triune not by a composition of parts but by a coexistence of persons” (QQ. et resp. ad orthod., q. 129). We proceed in this way. (1) Articles of faith must not be set against each other. Both the simplicity of the divine essence and the trinity of persons are set before us in the Word. Therefore both must be accepted with the obedience of faith. (2) We do not claim that the divine essence is distinguished really from the persons, as Sommer falsely attributes to us in his Refut. P. Carol., p. 25. Rather, we assert that the essence of God and the three persons of the Godhead are really and simply one. Therefore there is no composition here. (3) The personal properties do not multiply the divine essence nor are they compounded because one and the same divine essence is in the Father, Son, and Holy Spirit—in the Father as unbegotten, in the Son as begotten, in the Holy Spirit as proceeding. The Scholastics respond in this way: The question is not whether there is in God some real distinction that effects a real multitude or plurality but whether there are in God some real components that effect a real composition. The divine persons are indeed distinguished really, but they still are not extreme components that come together to compose something. (4) Sometimes the Photinians therefore urge: “Where there are three truly and really distinct persons, there is no longer pure and supreme simplicity.” But according to our hypothesis, there are in the divine essence three truly and really distinct persons. Here we limit the major premise: Where there are three truly and really distinct persons whose essence is not one and undivided, there is no longer pure and supreme simplicity. But there is one undivided essence of the three divine persons. (5) The person of the Father is not a composite of essence and personal property as of two things really diverse, but essence and unbegottenness are really one in the Father. Augustine, De Trinit., bk. 7, c. 6: “ ‘Being’ is not one thing in God and ‘person’ another; rather, they are completely the same.” The Scholastics say: “Hypostasis does not add to the essence some level of nature or some action but only the mode of being.” (See our De glor. Dei, disp. 10, thesis 36.)
§ 135. (IV) The question arises: Is the simplicity of the divine essence undermined by the distinction between the antecedent and consequent will? Piscator affirms this in his Not. ad tract. Vorst. de Deo at p. 62, thesis 27. We demonstrated the opposite in De glor. Dei, disp. 9, § 7. We do not establish in God a dual, really distinct will, which is one and undivided; rather, we explain a twofold respect of the one and undivided will.
(V) The question arises: Does simplicity introduce some perfection? Cajetan denies this because simplicity does not add any entity25 or positive mode but only the negation of compounding (just as unity brings in a negation of multitude). Nevertheless it should be remembered that this negation is established on a perfection. For in every genus, that which is more simple is also more perfect. (See Thomas, 1, Contra gent., c. 18.)
Practical use.
§ 136. God is utterly simple in His essence, so also is He in His will. There is no discrepancy here, no contradiction, nothing contrary and opposed to itself. James 1:5: “He gives to all people 
[simply].” May that beautiful simplicity adorn also our behavior, as we pray with David: “May integrity26 and uprightness preserve me” (Ps. 25:21). God is present with the simple; He is offended by cunning. Double-tongued people who “speak in heart and heart” (Ps. 12:[2])—that is, people whose words are not in harmony with the sense of their heart—are an abomination to God (Prov. 11:20). The simplicity of a dove, not the cunning of a serpent, is recommended to us (Matt. 10:16; Eph. 6:5). In 2 Cor. 1:12 it is called “the sincerity of God,” which God works and which is pleasing to Him.