The challenge of speaking about God, a being whose nature is entirely transcendent and unlike any created thing, has occupied theological and philosophical thought for centuries. How can finite human minds apprehend or even articulate truths about an infinite, uncaused cause? St. Thomas Aquinas, a towering figure in medieval philosophy and theology, proposed the doctrine of analogy as a sophisticated solution to this epistemic problem. Far from implying that our language about God is merely metaphorical or arbitrary, Aquinas argues that analogy allows for genuine, albeit limited, knowledge of God by relating divine attributes to created perfections in a principled way. This essay will explore Aquinas’s concept of the analogy of being, demonstrating how it provides a framework for understanding divine attributes like goodness and power as they are predicated of both God and creatures, preserving both divine transcendence and the intelligibility of our discourse about the divine.
Aquinas’s doctrine of analogy is rooted in his understanding of predication, the act of attributing a quality or characteristic to a subject. He distinguishes between equivocal, univocal, and analogous predication. Univocal terms are used in precisely the same sense when applied to different subjects, such as "dog" referring to both a canine and a constellation. Equivocal terms are used in entirely different senses, like "bank" referring to a financial institution and the edge of a river. Neither of these, Aquinas argues, can adequately describe our relationship to God. If terms like "good" or "wise" were univocal when applied to God and humans, it would imply an identity of essence that is impossible, given God’s infinite nature and our finite existence. If they were equivocal, our discourse would be meaningless, lacking any shared referent.
Analogy, for Aquinas, offers a middle ground. Analogous terms are predicated of different subjects in a way that is neither entirely the same nor entirely different. He primarily develops two forms of analogy: analogy of attribution and analogy of proportionality. Analogy of attribution holds that a term is predicated of different subjects according to their relation to a primary analogate. For instance, "healthy" can be predicated of a patient, a diet, and medicine. The primary analogate is the patient, in whom health intrinsically resides. The diet and medicine are called healthy insofar as they produce or sustain health in the patient. Aquinas applies this to God and creatures by asserting that divine perfections are the primary analogates. When we say God is good, we mean that God is the source and exemplar of all goodness. Created goodness is a participation in or derivation from this divine goodness. Thus, "good" is said of God in a primary sense and of creatures in a secondary, derived sense, all pointing back to God as the ultimate source.
The analogy of proportionality is perhaps more complex and directly addresses the difference in mode of being. This form of analogy asserts that a term is predicated of different subjects according to their different proportions or relationships to their respective perfections. For example, "seeing" can be predicated of a human and an eagle. While both "see," the mode of their seeing is vastly different, proportional to their respective faculties and natures. Aquinas extends this to God and creatures by suggesting that attributes like "intelligent" or "powerful" are predicated of God and creatures according to their respective proportions of being. God's intelligence is infinite and uncreated, while human intelligence is finite and created. Yet, the concept of intelligence itself, though imperfectly understood in its divine mode, can be meaningfully applied because there is a proportion between God’s being and God’s attributes, and between our being and our attributes. Our created perfections serve as imperfect reflections or likenesses of the perfect perfections found in God. This allows us to affirm that God possesses these perfections, not in the same way we do, but in a way that is appropriate to God’s unique, infinite existence.
The significance of Aquinas’s doctrine of analogy lies in its capacity to safeguard both divine transcendence and the possibility of meaningful theological language. It allows us to speak of God using terms derived from our experience of creation without falling into anthropomorphism or reducing God to the level of the created. When we say God is loving, we do not mean God experiences love as a human does, with the same passions and limitations. Instead, we mean that God is the supreme, infinite source and perfection of all that we understand as love, and created love is a faint echo of this divine reality. The analogy of being, therefore, provides a crucial hermeneutical tool, enabling theology to engage with revealed truths and philosophical inquiries about the divine with intellectual rigor and humility. It acknowledges the limits of human knowledge while asserting that these limits do not render discourse about the ultimate reality entirely impossible.