Divine Simplicity and Thomas Aquinas’s Philosophy

Philosophy often serves as a guiding tool for those seeking to lead a more meaningful life; however, the abundance of information available can sometimes create confusion. To address this, it is essential to return to foundational ideas, such as the philosophy of Thomas Aquinas and the concept of divine simplicity. These principles provide crucial insights that deepen our understanding and application of philosophy in life’s search for meaning. This article will explore the teachings of Thomas Aquinas, the notion of divine simplicity, and their importance in the philosophical quest for a more fulfilling existence.

Key features of Thomas Aquinas’s philosophy

Thomas Aquinas was a medieval philosopher and theologian whose ideas greatly influenced Western thought. One of his key contributions was combining Christian theology with the philosophy of Aristotle. He believed that faith and reason could work together to help people understand the world and their relationship with God. For Aquinas, reason was a gift that allowed humans to explore truths about the universe, while faith provided knowledge about divine mysteries that reason alone couldn’t explain.

Aquinas is well-known for his concept of “natural law,” which suggests that moral principles are rooted in the nature of humans and the world. He argued that humans have a purpose, and by using reason, they can discover how to live in alignment with that purpose, ultimately leading to happiness and harmony. His famous “Five Ways” are arguments for the existence of God, which include ideas like a “First Cause” and an “Unmoved Mover,” emphasizing that the universe’s very existence points to a divine creator.

Aquinas’s work bridges the gap between science, philosophy, and faith, offering a framework where belief in God and rational inquiry coexist. His emphasis on logic and ethics continues to influence discussions on morality, human rights, and theology today.

What is divine simplicity?

Thomas Aquinas viewed divine simplicity as a core attribute of God, meaning that God is not composed of parts or divisible in any way. For Aquinas, God’s essence is identical to His existence, which sets Him apart from all created beings. While created things have a distinction between what they are (essence) and the fact that they exist (existence), Aquinas believed that in God, there is no such distinction. God does not merely possess existence; He is existence itself.

Aquinas argued that this simplicity meant God is entirely unified and not subject to any form of composition, whether physical, metaphysical, or conceptual. This unity ensures that there is no division or complexity within God—no attributes or qualities exist as separate from His nature. Attributes such as goodness, power, and wisdom are not additional aspects of God but are understood to be identical to God’s essence. For Aquinas, this view highlighted the infinite and unique nature of God, emphasizing that God is self-sufficient and unchanging.

Ultimately, divine simplicity for Aquinas underscores the idea that God is wholly other, incomparable to anything within the created world, and completely self-contained as the ultimate source of all being. This understanding plays a fundamental role in how Aquinas describes the nature of God in his theological and philosophical works.

This example helps to demonstrate this philosophical perspective. Thomas Aquinas’s view about divine simplicity is evident in his argument regarding God’s nature and attributes. He believed that God’s attributes, such as wisdom, power, and goodness, are not separate parts but are identical to God’s essence. A simple example of this idea can be found in his explanation of God as a perfect unity. For instance, according to Aquinas, God’s wisdom is not something God possesses in addition to His essence; instead, His essence is wisdom itself. To help illustrate, think of light from the sun—it is not separate from the sun but a direct expression of it. Aquinas emphasized that God’s simplicity means there are no divisions or components in God’s being, which preserves the idea of God as both infinite and indivisible, free from any complexity or limitation that could compromise His perfection.

Challenges to Thomas Aquinas’s view about divine simplicity

Some philosophers object to or reject Thomas Aquinas’s view on divine simplicity for a variety of reasons. One common objection is that the concept of divine simplicity is difficult to reconcile with the idea of a personal God. Many religious traditions describe God as having attributes such as love, justice, mercy, and wisdom. Critics argue that divine simplicity, which suggests that God has no distinct parts or attributes, makes it challenging to understand how God can possess these qualities without them being separate from His essence. To some, this portrayal of God seems abstract and impersonal, deviating from the relational understanding often emphasized in many faiths.

Another concern is logical consistency. Some philosophers believe that divine simplicity creates contradictions. For instance, if God’s will, knowledge, and essence are identical under divine simplicity, it raises questions about how God can make free choices. If every aspect of God is the same, critics argue, it seems to leave no room for the kind of flexibility needed for God to choose one action over another. This issue can make God’s actions seem pre-determined or necessary, which might conflict with the traditional belief in God’s freedom.

Philosophers also challenge divine simplicity by pointing out that it can seem incompatible with our understanding of language. When humans describe God using attributes like “all-knowing” or “all-powerful,” these words seem to imply distinctions in God’s nature. However, if divine simplicity is true, then these distinctions do not exist in God. Critics claim this makes it difficult to understand what it even means to use these terms and whether they adequately describe God in any meaningful way.

Finally, metaphysical concerns arise. Some argue that the concept of divine simplicity leans too heavily on classical metaphysics, which may not align with more modern philosophical methods. Philosophers influenced by contemporary approaches sometimes reject the idea as unnecessarily abstract or overly reliant on ancient frameworks that they believe are themselves flawed.

These objections suggest that while the concept of divine simplicity strives to express God’s ultimate unity and perfection, it also raises profound philosophical questions that challenge its coherence and applicability.

Why divine simplicity is important to Thomas Aquinas’s philosophy

These are some of the main reasons why grasping the concept of divine simplicity is essential to comprehending Thomas Aquinas’s philosophy.

1. Foundation for Understanding God’s Nature

Divine simplicity is crucial because it underscores the idea that God is not composed of parts or divided in any way. This concept is key to understanding the nature of God as wholly unified and indivisible, which is essential for comprehending other attributes of God, such as omnipotence and omniscience. Without divine simplicity, it might seem that God’s attributes are separate from His essence, leading to confusion about how God can be consistent and unchanging. This foundational idea helps clarify that everything about God is unified within His being, which is a central theme in theological discussions.

2. Maintaining the Idea of God’s Perfection

The concept of divine simplicity is directly tied to the notion of God being perfect. If God were composed of parts, those parts would need to come together to create His being, which would suggest some sort of dependency or potential for imperfection. Divine simplicity eliminates this issue by emphasizing that God exists fully and perfectly without any dependency on external components. This understanding reinforces the idea that there is no flaw, changeability, or contingency in God, allowing for a clearer grasp of why God is considered the ultimate standard of perfection.

3. Laying the Groundwork for Divine Immutability

Divine simplicity is also important for grasping the attribute of divine immutability, which refers to God being unchanging. If God had parts, there would be a possibility for change as parts could alter or interact differently. However, with divine simplicity, God’s essence and existence are one and the same, which means there is no potential for alteration. This understanding supports the belief that God’s nature, promises, and will are constant, providing a stable basis for faith and trust in theological contexts.

Contrasting Thomas Aquinas’s philosophy with Baruch Spinoza’s philosophy

While both Thomas Aquinas and Baruch Spinoza focus on the concept of simplicity within their philosophies, they interpret it in fundamentally different ways, leading to contrasting views about God and existence. For Thomas Aquinas, divine simplicity means that God is utterly indivisible and lacks composition; God’s essence is existence itself, without any distinction within God’s being. This view is the foundation of his theistic framework, where God is both transcendent and personal, existing beyond the universe while being actively involved within it.

Spinoza, on the other hand, also presents simplicity in his philosophy, but he equates it with the oneness of substance. Spinoza argues in his work Ethics that everything in existence is a single substance, which he calls God or Nature. Unlike Aquinas’s transcendent God, Spinoza’s God is immanent, meaning God is not separate from the universe but is the universe itself. This pantheistic approach removes the distinction between creator and creation.

The key differentiation lies in their conception of God’s relationship with existence. For Aquinas, divine simplicity supports the notion of a personal God distinct from creation, while for Spinoza, simplicity leads to a system where God and existence are identical. This fundamental divide highlights the personal theism of Aquinas versus the impersonal monism of Spinoza.

Divine Simplicity, Thomas Aquinas’s philosophy and the philosophy of life

Reflecting on Thomas Aquinas’s view about divine simplicity, whether you agree with it or not, holds practical significance in shaping your personal philosophy of life. Philosophy isn’t just a theoretical exercise; it’s meant to inform how we see the world, ourselves, and our purpose. Engaging with ideas like Aquinas’s challenges us to think deeply and critically about fundamental questions, such as the nature of existence, unity, and the grounding of meaning in life. Even if divine simplicity itself doesn’t directly influence your beliefs, the process of examining it encourages intellectual humility and curiosity—both essential traits for personal growth.

One of the most valuable aspects of reflecting on Aquinas’s philosophy is the way it invites us to consider the interconnectedness of ideas. Aquinas’s work demonstrates a dedication to seeking clarity and coherence, values that can guide us in many areas of life. When developing your own philosophy, reflecting on his example promotes a disciplined approach to understanding complex concepts and prompts you to think about the consistency of your beliefs. Without such reflection, it’s easier to overlook contradictions or gaps in your worldview.

Additionally, reflecting on philosophical ideas like Aquinas’s cultivates a sense of open-mindedness. Whether you agree or disagree, engaging with a thought system from an open perspective broadens your understanding of human reasoning and the diversity of perspectives. This openness can enhance personal relationships, strengthen empathy, and improve your ability to communicate with others who hold different beliefs. It reminds us that wisdom often emerges from grappling with ideas that challenge or stretch our current views.

Ultimately, reflecting on Aquinas’s philosophy encourages a deeper engagement with life itself. It provokes questions about what truly matters and how we make sense of our experiences. Even if you conclude that Aquinas’s views don’t align with your own, the act of grappling with them sharpens your thinking and equips you to approach other philosophical or spiritual questions with greater insight. Philosophy, at its best, is a tool for creating meaningful lives, and Aquinas’s work provides a compelling foundation for this process.

Further reading

Aquinas, T. (2006). Summa Theologica. (Fathers of the English Dominican Province, Trans.). Christian Classics. (Original work published 1485)

Davies, B. (2014). Thomas Aquinas on God and Evil. Oxford University Press.

Kerr, G. (2015). Aquinas’s Way to God: The Proof in De Ente et Essentia. Oxford University Press.

McCabe, H. (2005). On Aquinas. Bloomsbury Academic.

Morris, B. (2021). Divine Simplicity and the Ineffable Maker of All Things. Cambridge University Press.

Stump, E. (2003). Aquinas. Routledge.

Te Velde, R. (2006). Participation and Substantiality in Thomas Aquinas. Brill.

Turner, D. (2013). Thomas Aquinas and the Metaphysics of Faith. University of Notre Dame Press.

Van Nieuwenhove, R. (2022). Thomas Aquinas and Contemplation. Bloomsbury Academic.