Aquinas & the Cosmological Arguments: Crash Course Philosophy #10

In this blog post, we discuss the cosmological arguments put forth by Thomas Aquinas, the renowned Italian theologian and philosopher. Aquinas sought to provide evidence for the existence of God through five distinct arguments, with the first four collectively known as the cosmological arguments. These arguments are grounded in observable phenomena and aim to establish the necessity of a First Cause or Unmoved Mover for the universe. Despite his firm belief in God's existence, Aquinas recognized the importance of presenting rational evidence to support his beliefs, which led him to construct these philosophical arguments. In this post, we will explore Aquinas' first four cosmological arguments, their logical basis, and some of the criticisms they have faced over time.

The Argument from Motion

Aquinas' first cosmological argument, known as the Argument from Motion, begins by observing the motion of objects in the world. He posits that everything in motion must have been set into motion by something else, creating a chain of causation. To avoid the problem of an infinite regress of movers, Aquinas proposes the existence of an Unmoved Mover, a static being that initiated motion in the first place. According to Aquinas, this Unmoved Mover is none other than God, the ultimate cause of motion in the universe.

The Argument from Causation

The second cosmological argument, the Argument from Causation, centers around cause and effect relationships. Aquinas reasons that every effect must have a cause, and a chain of causes and effects cannot extend infinitely backward in time. To escape the conundrum of an infinite regress of causes, he posits the existence of a First Causer, an uncaused cause. This First Causer, Aquinas identifies as God, serves as the ultimate origin of all causes in the universe.

The Argument from Contingency

Aquinas' third cosmological argument, the Argument from Contingency, draws a distinction between necessary beings and contingent beings. Contingent beings are those that could have not existed and depend on other things for their existence. Aquinas contends that an infinite regress of contingent beings is logically impossible. To account for the existence of contingent beings, he posits the necessity of at least one necessary being – a being that has always existed and cannot not exist. According to Aquinas, this necessary being is none other than God.

The Argument from Degrees

The fourth cosmological argument, the Argument from Degrees, revolves around the concept of measuring properties in relation to one another. Aquinas observes that properties come in degrees, and he suggests that the pinnacle of perfection against which everything else is measured is God. This argument implies the existence of a perfect being that defines the value of all other properties.

Criticisms and Weaknesses

While Aquinas' cosmological arguments were influential in their time, they have faced significant criticisms and objections over the years. One common criticism is that these arguments do not establish the existence of any specific god, leaving room for multiple interpretations or the possibility of polytheism. Additionally, the arguments do not necessarily lead to the existence of a sentient or personal God, as described in various religious beliefs.

Two key objections against Aquinas' arguments are worth noting. Firstly, some philosophers question the assumption that there cannot be an infinite regress of causes or motion. They argue that infinite regress might be possible, which challenges the necessity of a First Cause or Unmoved Mover. Secondly, there is the objection that Aquinas' arguments are self-defeating. If everything requires a cause or a mover, then the same principle should apply to God, raising questions about God's own existence.

Thomas Aquinas' cosmological arguments represent a significant contribution to the philosophical exploration of God's existence. While Aquinas firmly believed in God, his arguments have faced critical evaluation and various objections. These arguments have sparked numerous philosophical debates and continue to provoke discussions about the nature of God and the existence of a First Cause. Engaging with these arguments allows us to participate in an ongoing intellectual conversation, contributing to the timeless pursuit of understanding the mysteries of the universe and the divine.