What does simplicity exclude, and how do its six accomplishments establish that exclusion?

Actuality and unity

Pure actuality asks whether the source requires an actualizer to possess its actuality. If that perfection is received, the explanation has not reached the ultimate in that respect. Pure actuality therefore concerns freedom from receptive actualization. Its positive relation to productive power requires further attention.

Non-derivative unity asks what makes the source one. A whole unified through prior factors or a coordinating principle depends upon what supplies that unity. The divine source cannot be ultimate through a unity it receives from something more basic. This excludes assembled deity while leaving the real personal distinctions of the Trinity intact.

Constitution and common measure

Anti-composition concerns constituents whose combination explains or conditions the whole. The argument identifies these parts and shows how the source depends upon them. Calling every difference a part would beg the question. A distinction's reality, constitutive role, and explanatory priority are claims that can come apart.

No genus or common measure asks whether a wider kind or principle constitutes and delimits deity. God cannot receive divine determination from a framework more ultimate than God. A shared concept is not automatically such a framework. Logical predication and mathematical representation do not become superior realities merely because they can describe something truly.

Existence and essential perfection

Essence–existence identity addresses a subject that receives existence through a distinct actualizing principle. Such a recipient would not explain its own existential actuality. The classical conclusion is that God's essence is subsistent existence. Establishing that identity requires the account of reception and actuality; merely denying an external cause leaves the argument incomplete.

Attribute simplicity asks whether wisdom, goodness, and power function as distinct perfecting principles that complete God. Their intelligible contents remain different, while their divine realization is undivided. Simplicity excludes acquired or assembled essential perfection. It does not make the names synonymous, erase personal origin, or supply positive attributes without their own warrant.

Why actuality and unity require different arguments

The argument about actuality begins with a specified reception: a subject possesses some actuality because another principle actualizes it. If that received actuality is what makes the subject capable of being the ultimate source, the proposed terminus still borrows what explains its sourcehood. The explanatory demand that brought us to a source therefore remains unsatisfied. Applied comprehensively, this excludes a divine actuality constituted through receptive actualization. It does not establish every claim associated with pure act merely from the absence of an external cause; the question concerns intrinsic actualizers as well as external producers.

Unity asks a different question. Several independently specified factors do not, merely by existing, explain why they are one operative reality. If an arrangement, connecting relation, or coordinating power supplies that unity, the whole depends upon it precisely as one. An absolute source cannot owe its identity as one source to such a prior unifier. The conclusion is underived unity. A rival may instead posit a fundamentally unified whole whose features depend upon it. That rival has rejected the account of unity being criticized; it has not contradicted itself merely by admitting differentiation.

When constituents and measures explain what a thing is

Constitution concerns what makes a whole the reality it is. Where constituents supply essential actuality to a whole, the whole cannot be actual in that respect apart from their contribution. This dependence can remain even if nobody assembled the whole and even if the constituents necessarily coexist. Necessity does not reverse explanatory priority. The argument against composition therefore excludes structures in which God is actual through more basic contributions. It reaches further only with the additional premise that every genuine intrinsic composition involves such constitutive dependence. A whole-priority theory directly contests that premise.

The common-measure argument concerns specification rather than assembly. If a wider nature supplies what deity is, and an additional differentiating principle makes this instance divine in its particular way, deity is explained through a framework it does not originate. This conflicts with unrestricted sourcehood in determination. But two things falling under our concept of actuality does not establish a shared constituent nature above them. The route excludes an ontologically prior measure, not truthful common predication. Otherwise the argument would confuse the order of our descriptions with the order of reality.

Why intrinsic composition is a way of depending

There is a positive reason to connect composition with dependence. Consider an organized living body. Its constituents are identifiable through their intrinsic activities and organization; they are not inferred merely from our having several descriptions. The complete body's actuality includes contributions that no constituent supplies alone. Its being this living whole therefore obtains through an internally articulated realization. We can recognize the constituents and their work before asking whether such realization is compatible with absolute sourcehood.

The general argument concerns that work. Where numerically distinct intrinsic realities jointly constitute one complete reality, the whole's actual being includes their contributions and their unity. Calling the whole uncaused does not eliminate either condition. Its complete actuality is not supplied by any contributor alone; the contributors are actual together in an order that constitutes this whole. This is constitutive dependence, even where no external agent assembles anything. The whole is actual through a structure of intrinsic contributions rather than being the undivided actuality that realizes every essential perfection.

The underlying principle is that a real constitutive explanation cannot disappear when its subject is called ultimate. If distinct principles genuinely account for the subject's intrinsic actuality, that actuality is conditioned by their contribution. The source sought by the argument must explain such conditioned actuality without reproducing it within its own essential being. Otherwise the explanatory ascent has stopped at another instance of the condition it set out to explain.

Why whole-priority and necessity do not settle the question

A whole can be prior to its parts in one respect while depending on their contribution in another. An organ has its functional identity through the living organism, yet the organism lives through its organs' coordinated activities. Whole-priority explains why these are organs of this organism. It does not by itself explain away the intrinsic realization through which the organism lives. Recognizing both directions need not produce a vicious circle, because the explanatory respects differ. But neither direction establishes an actuality free from every form of reception.

Aquinas's act-and-potency argument reaches this point from another side. In composition, either one principle actualizes another, or the constituents are incomplete relative to the actual whole. Their being united is an actuality not supplied by their plurality merely as plurality. A whole-priority account may locate the actualizing principle in the whole itself. It then explains the constituents as internally actualized through that whole; it has not yet shown that no receptive realization belongs intrinsically to the complete reality. Absolute pure actuality excludes intrinsic receptive principles as well as an external actualizer.

Making every constituent necessary does not remove this structure. Necessity answers whether the constituent or union could fail to exist; constitution answers through what the whole is actual. An eternal, necessarily organized whole could still possess its complete actuality through distinct principles. Their inseparability blocks a story about disassembly. It does not make their contributions numerically identical or explain why their union requires no actualizing basis.

What the existence and perfection arguments require

The essence–existence route examines a real recipient–actualizer structure. If what a subject is does not include its existential actuality, and a really distinct act supplies that actuality, the subject exists through that act. A recipient of existence cannot be ultimate in existence. On the classical account that any real essence–existence distinction has this receptive structure, the ultimate source is not a recipient with existence added: its essence is its existing. A rival that treats essence and existence as primitively distinct but neither explanatory of the other challenges that account. Uncaused existence alone does not refute the rival.

The attribute route begins only after a positive perfection has been warranted. If wisdom perfects a subject through a really distinct actualizing principle, that subject owes its wisdom to the principle's contribution. Underived wisdom cannot belong in that way. The proposed simple realization is one concrete actuality that is genuinely understanding, effective, and good, while understanding, efficacy, and goodness answer different questions. To conclude that there is exactly one realizer, however, we must exclude necessarily coexisting distinct realizers that do not complete a more basic subject. Naming several perfections does not supply that exclusion.

Real perfections need no added perfecting realities

This argument supports attribute realism without making every attribute a constituent. Wisdom concerns understanding truth; power concerns efficacy; goodness concerns perfection and right willing. These contents differ objectively. Their truth need not be produced by our concepts, and their realization need not involve three additional intrinsic things. One concrete actuality can genuinely understand, act effectively, and will the good. Its being adequate to several truthful predications does not make those predications synonymous.

The positive case for this unity is explanatory. If the same complete actuality supplies everything required for the warranted perfections, separate intrinsic actualizers add no needed completion. If instead distinct realities supply indispensable contributions, the constitutive-dependence argument applies. One undivided realization thus explains both the perfections' truth and their underived possession, without a further subject awaiting their contribution or a nexus joining several perfecting acts. This is an argument for the account's adequacy and unity, not a rule that explanatory redundancy proves nonexistence.

The strongest rival posits primitive intrinsic differentiations that neither actualize a recipient nor combine to complete God. That proposal cannot be rejected simply because its distinctions are real. It must explain what makes them distinct realities, rather than different truths about the same reality, and why their intrinsic plurality involves no constitutive conditions. The classical account has a substantive advantage: one actual source realizes the perfections, while different positive contents explain our different predicates. The rival's primitive differentiation remains an additional metaphysical commitment.

The strongest property and whole accounts

A property theorist can say that God's wisdom is real without being a part or an ingredient. A whole-priority theorist can say that God's differentiated features are explained by the one fundamental reality. The proper reply asks what makes each attribution true. If an additional intrinsic actualizer supplies the perfection, the dependence argument applies even without parthood. If the whole itself fully realizes it, that proposal may agree with the central account. If irreducibly distinct intrinsic features remain without any supplying actuality, their exclusion needs a stronger theory of constitution. The six routes establish specific exclusions as their premises succeed; their convergence does not convert underivedness alone into a completed proof against every differentiated ultimate.

What the six arguments establish together

The six accomplishments apply this reasoning in distinct respects. Pure actuality excludes an intrinsic recipient needing actualization. Non-derivative unity excludes coordination through which several factors become one source. Anti-composition excludes distinct contributions constituting essential divine actuality. No genus or common measure excludes a prior determinable nature whose further specification makes this instance what it is. Essence–existence identity excludes a recipient whose existential actuality is supplied through a distinct act. Attribute simplicity excludes a divine subject perfected through additional essential actualizers. The arguments overlap because actuality, existence, unity, and perfection concern the same reality under different explanatory questions.

Their strongest common conclusion is that the absolute source cannot possess its essential actuality through genuine constitutive contributions, whether external or intrinsic, temporal or eternal, contingent or necessary. This is stronger than merely denying an outside maker. It gives a reason for undivided divine realization: the source does not owe what makes it actual, one, existent, determinate, or perfect to internally completing realities. The six routes organize that case; they are neither a seventh proof nor an exhaustive classification of every possible ontology.

A completely general exclusion of primitive holistic differentiation still requires defending the classical claim that genuine intrinsic composition includes receptive or contributory principles. The reasons above support that claim wherever the proposed constituents actually do constitutive work. They do not turn every real distinction, including personal origin, into composition by definition. Catholic simplicity is received in theology; this philosophical account explains its force through a definite, independently assessable theory of actuality and constitution.