Thomism: Aquinas, Analogy, and the Rule It Was Missing
Thomism is the philosophical and theological school that grew from the work of Thomas Aquinas (1225–1274), and it holds that his answers to the questions of being, knowledge and value fit together as one system. Thomism's claims about God lean on a single doctrine, analogy, which says our words are true of God in a sense neither identical to their sense of creatures nor wholly different from it. It also has a weak point that Thomists and their critics have argued over for seven centuries: it names the middle ground between the two senses without stating the rule for crossing it. The Many Beings Framework keeps Aquinas's answer and supplies that rule.
Key takeaways
- Thomism is an integrated system. It joins Aristotle to Christian doctrine, and since Aeterni Patris (1879) it has anchored Catholic philosophy.
- Analogy carries the weight. Thomism says our words apply to God analogically, neither univocally nor equivocally.
- The weak point is the missing rule. Analogy does not state which words may cross from creature to God, or what ties both senses to one reality. Duns Scotus pressed that gap; Thomas Williams presses it still.
- Frame-Indexed Classical Theism supplies the rule. It keeps the Thomist middle, grants Scotus that something must stay univocal, and states which terms carry their frame: one reality, known whole in God's frame and truly but in part in ours.
What is Thomism?
Thomism is the school of philosophy and theology that takes Thomas Aquinas as its master. Aquinas was a Dominican friar who joined Aristotle's account of nature, cause and knowledge to the teaching of the Church, and the Church later named him a Doctor. What makes his followers a school is the conviction that his answers hang together as one body of thought, so that Thomism is studied as a system and defended as a system. The Thomist holds that what Aquinas says about being governs what he says about knowledge, that what he says about knowledge governs what he says about God, and that pulling one thread moves the rest.
The school has come in waves. Britannica divides its history into four periods: the two centuries after Aquinas's death, the sixteenth century, the revival that ran from about 1850 to the Second Vatican Council (1962–65), and the decades since. The revival took its charter in 1879, when Pope Leo XIII issued the encyclical Aeterni Patris and set Thomistic philosophy at the center of Catholic education. In 1914 Pius X went further. His Doctoris Angelici declared the capital theses of Aquinas's philosophy to be foundations of the whole science of natural and divine things, and that same year twenty-four Thomistic theses were published as the core of the system.
Thomism today is several schools sharing one master. Neo-scholastic, existential, transcendental, River Forest and Lublin Thomists each read Aquinas from a different starting point and disagree about a good deal. Analytical Thomism reads him with the tools of contemporary analytic philosophy, and it is the conversation a reader arriving from philosophy of religion is most likely to be in already. For all their differences, the schools agree on two things: Aquinas's answers form a whole, and the whole is still worth defending.
Free — the complete book
Get Volume One free.
The complete book, not a sample. The fastest way to test whether the framework holds.
No spam. Unsubscribe in one click.
What are the core doctrines of Thomism?
Four doctrines carry most of the system, and each of them says something about God.
The first is act and potency. A thing in potency can become what it is not yet; a thing in act already is what it is. Change is the passage from one to the other, and finite things are a mixture of both. God alone is pure act (actus purus), with no unrealized potential in Him, and from this Thomism concludes that He does not change.
The second is the distinction between essence and existence. What a creature is and that it is are distinct: a horse's nature does not include the fact of its existing. In God the two are identical. His essence is to exist, and that identity grounds the Thomist doctrine of divine simplicity.
The third is hylomorphism, the teaching that bodily things are composed of matter and form. The human soul is the form of the human body, and so Aquinas holds together a spiritual soul and an embodied person without dividing the one man into two.
The fourth is natural theology, reasoning from the world to its cause. Aquinas's Five Ways argue from motion, from the order of efficient causes, from things that are able to be and not to be, from degrees of goodness and truth among beings, and from the way things without intelligence act for an end. When he argues that God's existence can be demonstrated at all, he cites Paul:
"For since the creation of the world God's invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse." (Romans 1:20, NIV)
Set the four side by side. God is pure act. God's essence is His existence. God is the first cause. Each sentence uses words we learned from creatures. If those words mean in God exactly what they mean in a horse, God becomes a very large creature. If they mean something wholly different, the sentences say nothing we can understand. Whether Thomism stands depends on a third possibility, and Aquinas gave it a name.
Volume Four works through pure act and divine changelessness at length in Resolving Immutability & Interaction.
What is analogical predication?
Analogical predication is the use of one word of two things in senses that differ but are related, so that the word is true of both without meaning exactly the same thing in each. Aquinas lays out the options in the Summa Theologiae, First Part, Question 13, and rules out two of them before settling on the third.
Words cannot be said of God and creatures in exactly the same sense. "Univocal predication is impossible between God and creatures," he writes, because "all perfections existing in creatures divided and multiplied, pre-exist in God unitedly." Nor can they be said in wholly unrelated senses, for then "from creatures nothing could be known or demonstrated about God at all." What remains is analogy: "these names are said of God and creatures in an analogous sense, i.e. according to proportion." His example is health. We call an animal healthy and we call medicine healthy, and the word does real work in both places, because medicine is the cause of the health the animal has.
The Thomist's strongest resource sits two articles earlier. As regards what a name such as "good" or "wise" signifies, Aquinas says, "they belong properly to God, and more properly than they belong to creatures." As regards the mode of signification, the way the word carries its meaning, it fits creatures, because creatures are where we learned it. Our words reach God truly and hold Him imperfectly. The Fourth Lateran Council had drawn the same boundary in 1215, teaching that between Creator and creature no likeness can be noted so great that a greater unlikeness cannot be seen between them.
Which kind of analogy Aquinas meant is still disputed. Some interpreters read him as holding an analogy of attribution, where one thing has a property first and others are named from their relation to it, as medicine is named from health. Others read him as holding an analogy of proportionality, where God's goodness stands to God's being as a creature's goodness stands to a creature's being. The Stanford Encyclopedia's entry on medieval theories of analogy traces the dispute. Cardinal Cajetan championed proper proportionality as analogy in the strict sense, and that reading became the standard Thomist defense against the followers of Scotus. In the twentieth century Erich Przywara's Analogia Entis (1932) gave the phrase analogia entis, the analogy of being, its modern weight as a name for the whole relation between Creator and creature.
Where is the doctrine of analogy weakest?
The doctrine tells us two things about a word said of God: its sense there is related to its sense of creatures, and the two senses differ. What it does not supply is the rule. It does not say which words may cross from creature to God, what happens to a word in the crossing, or what guarantees that the two senses concern one reality and not two things that happen to share a name.
That gap is where the objection lives, and by the start of the fourteenth century Duns Scotus had found it. His argument begins from a premise Thomism accepts: we formed our concepts from creatures. If so, the concepts we apply to God must be those same concepts. If they merely resemble them, as the analogist says, we have no concept of God at all. He added a test: a concept is univocal when affirming and denying it of the same thing would be a contradiction. A person can be certain that something is a being while doubting whether it is a substance or an accident, so the concept of being is one concept, prior to that difference. Without it, Scotus concluded, neither metaphysics nor theology would be possible. Thomas Williams's entry on John Duns Scotus adds that this is a claim about concepts and meaning. Scotus did not hold that God and creatures are the same kind of being. He held that the concept of being is the same concept when applied to both.
Williams pressed the argument further in 2005, in "The Doctrine of Univocity Is True and Salutary." Take "wise" said of God. Either we can state what it means there, or we can state how that meaning relates to its meaning of a wise man, or we can do neither. If neither, we have fallen into equivocation and do not know what we are saying. If either, we have restated the claim in words carrying their ordinary meaning, which is univocity by another route. The three options, Williams concludes, "in fact reduce to two: either unintelligibility or univocity."
The doctrine draws fire from the opposite flank as well. Karl Barth, in the preface to the first volume of his Church Dogmatics, wrote of the analogy of being: "I regard the analogia entis as the invention of Antichrist, and I believe that because of it it is impossible ever to become a Catholic." He later allowed that if the analogy of being were read as an analogy of faith, he would no longer say nasty things about it. In recent decades Catherine Pickstock (2005) and others in Radical Orthodoxy have traced secular modernity back to Scotus's univocity, and Richard Cross (2001) has replied that their history misreads him. The question Aquinas took up in the thirteenth century is still open in the journals.
Thomism has a reply to Scotus, and it carries weight. Cajetan's proportionality explains how the two senses relate: God's wisdom stands to God as ours stands to us. What the reply does not provide is a test that tells in advance when a particular use of a word has crossed the boundary illegitimately. An analogy that cannot be violated can absorb any objection brought against it, and an answer that cannot fail is not yet an answer.
Here the difficulty is at its sharpest. The doctrine leaves us holding two senses of one word, one for God and one for man, and admits that they are not the same. Unless something tells us what makes both of them senses of one reality, it is hard to accept that we have said anything true about God at all.
Volume One derives the rule this gap calls for from two axioms, before it touches a single dilemma; download it free.
How does Frame-Indexed Classical Theism resolve it?
Frame-Indexed Classical Theism (FICT) is a research program in analytic theology that resolves classical theological dilemmas by diagnosing them as artifacts of a single formal error. It is the Many Beings Framework's position, and it meets the weak point by supplying the rule analogy left unstated. With Thomist analogy, FICT holds that God-talk is neither univocal nor equivocal. With Scotist univocity, it holds that analogy needs something univocal beneath it. What it adds to both is the rule.
The framework begins from two axioms. A being's nature is the fusion of its essential qualities. A conscious being's mode of existence determines its mode of apprehension. So beings whose natures differ in kind apprehend reality in perceptual frames that differ in kind, and the Creator and the creature differ in kind more deeply than any two creatures do.
Begin on God's side. In the Absolute Metaphysical Frame, God's own mode of knowing, there is one unified reality, known whole, without succession or ignorance. Then take our side. In the Human Finite Frame, the sequential, embodied mode proper to human nature, that same reality arrives in parts and in order, because a finite mind cannot hold the infinite in a single act. The layering is a feature of the apprehending; the reality apprehended is one and whole. There is one reality and two modes of access to it, and the second is bounded and true.
So our knowledge of God is intellectual, and it is not perceptual. By reasoning from what has been made, by testimony and above all by revelation, we know God truly, and our words refer to Him. We cannot apprehend Him as He apprehends Himself, because our nature confines our apprehension to our frame. Paul marks the boundary and its end:
"For now we see only a reflection as in a mirror; then we shall see face to face. Now I know in part; then I shall know fully, even as I am fully known." (1 Corinthians 13:12, NIV)
With that in place, the rule analogy lacked comes into view, and it meets each part of the weak point.
The index is grounded in natures. The framework started from natures and derived that frames differing in kind cannot share the frame-native meaning of certain terms, before any dilemma was in view. The index records a difference in being. An author may not attach it wherever an argument is going badly.
The rule says in advance which words carry their frame. Terms whose content involves time, possibility, agency or value carry the frame they are said from: free, good, now, able. Identity, non-contradiction and arithmetic mean the same thing in both frames. Because the list is stated, a use that breaks it can be caught, and a framework that can be caught out can be tested.
Both indexed senses refer to one reality. "Good" said from God's frame and "good" said from ours are two senses of one word, and both are senses of one thing: the reality God's frame grounds and sustains. That shared reference secures the truth of the analogy, and the bare doctrine left it unstated.
Return to Williams's dilemma. He asks what stays fixed when a word crosses from creature to God. The framework answers that the terms of logic stay fixed, and so does what both senses refer to: the one reality God's frame grounds. The logical terms are univocal, and Scotus was right to insist that something must be. What carries the index is the frame-sensitive content, which cannot be pressed into one sense without making the Creator a creature. Scotus made being itself univocal. The framework keeps univocity for logic and arithmetic, holds both senses to one shared reality, and leaves being where Thomism left it, said of God and creatures analogically.
The framework names the error of treating a frame-sensitive word as though it meant the same thing in both frames: the Many Beings Fallacy. The classical dilemmas the series takes up, from divine sovereignty and human freedom to the problem of evil, each commit it, and each dissolves once the index is restored.
FICT does not replace Thomism. It is the closest contemporary heir of Thomistic analogy, with the rule for the crossing written down, and it grants Scotus that something must stay univocal, locating it in logic and arithmetic. The statement of Frame-Indexed Classical Theism sets out the axioms and the rule in one place.
Volume One carries the argument from two axioms to the Many Beings Fallacy, each step shown; get your free copy.
How the positions compare
Each position below gets something right, and the comparison turns on what each leaves unsettled.
| Position | How words apply to God | What it gets right | What it leaves open |
|---|---|---|---|
| Thomist analogy (Aquinas, Cajetan) | In related senses, according to proportion | God-talk is neither univocal nor equivocal; the mode of signification is ours | No stated test for when a crossing is illegitimate |
| Scotist univocity (Scotus, Williams) | Core concepts in the same sense, with God and creatures differing in mode, infinite and finite | Meaningful God-talk needs something univocal beneath it | Makes being itself univocal |
| Frame-Indexed Classical Theism | Frame-sensitive terms indexed to their frame; logic and arithmetic univocal; one reality behind both senses | Keeps analogy and states its rule | Fails if a dilemma in its catalog does not turn on a frame-sensitive term carried across unindexed |
Frequently asked questions
Is Thomism only a Catholic position?
Thomism grew inside the Catholic Church and remains its reference point, but the instinct behind analogy runs wider. The Reformed theologian Francis Turretin, in his Institutes of Elenctic Theology, divides theology into archetypal theology, God's infinite knowledge of Himself, and ectypal theology, the finite knowledge fitted to the creature. That distinction reaches for the boundary Aquinas marked with analogy, and the Many Beings Framework counts it among its sources alongside Aquinas and Boethius. For how the framework reads a Reformed debate, see the article on TULIP Calvinism.
What is the difference between Thomism and Scotism?
Thomism follows Aquinas in holding that words such as "being," "good" and "wise" apply to God and creatures analogically, in senses related by proportion. Scotism follows Duns Scotus in holding that the concept of being applies to both univocally, with the same meaning, while God and creatures differ in the mode of what is meant: infinite in God, finite in us. Scotus is also known for his formal distinction, which holds that attributes such as God's wisdom and justice are one in reality and distinct in account.
What is univocity?
Univocity is the use of a word in exactly the same sense of two things. The univocity of being is Scotus's thesis that the concept of being is the same concept said of God and of creatures. William Alston argued in 1985 that functional concepts allow a degree of univocity between God and creatures. Frame-Indexed Classical Theism grants univocity to identity, non-contradiction and arithmetic, and withholds it from terms whose content involves time, possibility, agency or value, where Thomist analogy and Scotist univocity each claim the ground for themselves.
Is Thomism still relevant today?
Analytical Thomism has brought Aquinas into contemporary philosophy of religion, and the analogy debate at the center of this article is still argued in print. In 2005 Modern Theology carried Catherine Pickstock and Thomas Williams on opposite sides of Scotus's univocity. A doctrine that still divides philosophers seven centuries after its author's death is a live position.
Isn't frame-indexing just relativism?
Relativism makes truth vary with the one who holds it. The framework holds that there is one reality, that God's frame is its ground, and that the human frame is a real but bounded mode of access to that same reality. Two frames report on one world, and both reports are true. What differs between them is the mode of apprehension, and natures set that difference before any knower weighs in.
Where to go from here
Aquinas was right about the middle. Words said of God are neither univocal nor equivocal, and the Thomist who holds that line holds the truth. What the doctrine lacked was the rule for the crossing: which words cross, what changes when they do, and what keeps both senses tied to one reality. The Many Beings Framework was built to state that rule.
Volume One sets out the two axioms, derives the frames and names the fallacy, and it is free to download. Volume Four, Resolving Immutability & Interaction, carries the same rule into pure act and divine changelessness, where Thomism does its heaviest work, and it is available now in every format. The rest of the series takes the rule through time, evil, infinity and providence.
