Aristotle and Thomas Aquinas, two influential philosophers and theologians, provided arguments to support the existence of God.
While their approaches differ, they both presented rational and philosophical justifications for the existence of a supreme being. Here, we will discuss their key arguments.
- Aristotle’s Unmoved Mover: Aristotle argued for the existence of an “Unmoved Mover” based on his observations of motion and change in the world. He posited that everything in the natural world is in a state of constant change and motion. However, this chain of causation cannot go on indefinitely, as it would lead to an infinite regress. Thus, there must be an ultimate cause or source of motion that initiates and sustains all other motions. Aristotle concluded that this Unmoved Mover, which itself is not subject to change or motion, is God.
- Aquinas’ Five Ways: Thomas Aquinas presented five arguments, often referred to as the Five Ways, in his work “Summa Theologica.” These arguments are:
- First Way (Argument from Motion): Aquinas posited that everything in the world is in motion, and for something to be in motion, it must be moved by something else. However, this chain of motion cannot be infinite, so there must be an unmoved mover, which is God.
- Second Way (Argument from Efficient Causes): Aquinas argued that everything in the world has a cause, and causes form a chain of events. However, this causal chain cannot be infinite, so there must be a first cause, which is God.
- Third Way (Argument from Contingency): Aquinas suggested that everything in the world is contingent, meaning it depends on something else for its existence. However, if everything were contingent, there would be a time when nothing existed. Thus, there must be a necessary being, which is God, that does not depend on anything else for its existence.
- Fourth Way (Argument from Degrees of Perfection): Aquinas observed that things in the world have varying degrees of perfection and goodness. There must be a standard against which these degrees are measured, and this standard is God.
- Fifth Way (Argument from Design): Aquinas argued that natural objects in the world exhibit a purposeful order and complexity, which implies the existence of an intelligent designer, and that designer is God.
These arguments put forth by Aristotle and Aquinas offer philosophical justifications for the existence of God based on observations of the natural world, causation, motion, and order. While these arguments have been subjected to criticism and further philosophical inquiry, they remain influential in the field of philosophy of religion and continue to be debated and discussed by scholars and theologians.