The Argument from Design as Proof of God

The final of Thomas Aquinas’s Five Ways, the Fifth Way, explores the order and purpose evident in the natural world to demonstrate the existence of God. Known as the Argument from Design, this proof is found in the Summa Theologica (I, Q. 2, Art. 3). Aquinas observes that non-intelligent beings consistently act toward ordered ends, which implies a guiding intelligence. As philosopher Edward Feser notes:

“The Fifth Way provides one of the most striking arguments for God, compelling us to see purpose and design not as illusions but as realities rooted in a divine mind.”¹

The Fifth Way Explained: Order and Purpose in Nature

Aquinas begins with the observable fact that natural objects act toward specific ends. For instance, the acorn grows into an oak tree, rivers flow to the sea, and the planets follow predictable orbits. These patterns demonstrate purpose and regularity. Yet, these objects lack intelligence and cannot direct themselves toward their ends without guidance. Aquinas writes:

“Whatever lacks intelligence cannot move toward an end, unless it is directed by some being endowed with knowledge and intelligence.”²

Just as an arrow requires an archer to guide it to its target, so too do the purposeful actions of unintelligent beings require a directing intelligence. Aquinas concludes:

“Therefore, some intelligent being exists by whom all natural things are directed to their end; and this being we call God.”³

Philosophical Foundations: Teleology in Nature

The Fifth Way is grounded in the concept of teleology, derived from Aristotle’s philosophy. Teleology refers to the inherent purpose or goal-directedness of things. For example, the heart pumps blood to sustain life, and rain nourishes crops. Aquinas argues that this purposefulness cannot arise from chance or randomness but must ultimately be directed by an intelligent cause.

Philosopher Eleonore Stump explains:

“The Fifth Way invites us to see the natural world not as a chaotic accident but as a tapestry of purpose woven by an intelligent mind.”⁴

Contemporary philosopher Thomas Nagel, though not a theist, echoes the significance of teleology:

“The appearance of design in the universe is so overwhelming that it cannot simply be dismissed as an illusion. It demands explanation.”⁵

Aquinas’s Fifth Way does not merely claim that order exists but that the order we observe is best explained by a transcendent intelligence.

Theological Implications: God as the Supreme Designer

The intelligent being identified in the Fifth Way is the God of classical theism, who creates and sustains the universe with order and purpose. This aligns with the biblical description of God as the Creator, such as in Psalm 19:1: “The heavens declare the glory of God, and the sky above proclaims his handiwork.”

Timothy Keller highlights the theological significance of this argument:

“The intricate design of the natural world points to a Creator who is not only powerful but intentional, weaving purpose into every part of creation.”⁶

Moreover, Aquinas’s Fifth Way challenges modern assumptions of a purposeless universe. As John Lennox writes:

“Far from being a random accident, the universe exhibits an order and intelligibility that reflect the mind of its Creator.”⁷

This argument not only identifies God as the designer but also emphasizes His wisdom and intentionality in creation.

Responding to Objections

1. The Illusion of Design:

Some critics argue that the order in nature is a result of random processes and natural selection. However, as Edward Feser explains:

“Natural selection accounts for the adaptation of organisms, but it presupposes the existence of laws and regularities that themselves require explanation. The Fifth Way addresses the ultimate source of these laws.”⁸

2. The Multiverse Hypothesis:

Others suggest that a multiverse could explain apparent design, with countless universes producing one with order by chance. Philosopher Robin Collins counters:

“Even the multiverse hypothesis depends on fine-tuning to produce life-supporting universes, pointing back to an intelligent cause.”⁹

3. Why Not a Naturalistic Explanation?

Some argue that natural processes alone can explain order. However, Eleonore Stump points out:

“Naturalistic explanations describe mechanisms but fail to account for why these mechanisms exist or why they are goal-directed. The Fifth Way addresses the source of this teleology.”¹⁰

Contemporary Relevance

The Fifth Way remains profoundly relevant in light of modern scientific discoveries. The intricate complexity of the universe, from the fine-tuning of physical constants to the information encoded in DNA, aligns with Aquinas’s observations of purpose and design. As astrophysicist Paul Davies states:

“The impression of design is overwhelming. The universe appears to have been fine-tuned for life, pointing to an underlying purpose.”¹¹

Aquinas’s argument transcends specific scientific theories, addressing the ultimate question of why nature is intelligible and ordered. John Lennox emphasizes:

“Science reveals the fingerprints of a designer, but it is philosophy and theology that point us to the divine mind behind those fingerprints.”¹²

Order and the Divine Mind

The Fifth Way is a compelling argument for the existence of God, rooted in the observable order and purpose in the natural world. By demonstrating that unintelligent beings act toward specific ends, Aquinas leads us to the necessity of a directing intelligence. As Aquinas concludes, “This being we call God.”¹³

This argument invites us to marvel at the order and intelligibility of creation, recognizing in it the work of a wise and purposeful Creator. The Fifth Way is not just a proof of God’s existence; it is a call to worship the Designer who sustains all things with intention and wisdom.

¹ Edward Feser, Aquinas: A Beginner’s Guide (London: Oneworld, 2009).

² Thomas Aquinas, Summa Theologica, I, Q. 2, Art. 3.

³ Ibid.

⁴ Eleonore Stump, Aquinas (London: Routledge, 2003).

⁵ Thomas Nagel, Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False (Oxford: Oxford University Press, 2012).

⁶ Timothy Keller, The Reason for God (New York: Dutton, 2008).

⁷ John Lennox, God’s Undertaker: Has Science Buried God? (Oxford: Lion Hudson, 2009).

⁸ Feser, Aquinas: A Beginner’s Guide.

⁹ Robin Collins, The Fine-Tuning of the Universe for Intelligent Life (Oxford: Oxford University Press, 2003).

¹⁰ Stump, Aquinas.

¹¹ Paul Davies, The Goldilocks Enigma: Why Is the Universe Just Right for Life? (London: Allen Lane, 2006).

¹² Lennox, God’s Undertaker.

¹³ Aquinas, Summa Theologica, I, Q. 2, Art. 3.