“It is necessary to posit something which is necessary of itself, and has no cause of its necessity outside of itself but is the cause of necessity in other things. And all people call this thing God.”
- 1225 – March 7, 1274
- Born in the Kingdom of Sicily (Italy)
- Theologian, philosopher
- A representative figure of scholasticism, who systematized the relationship between the doctrines of the Catholic Church and reason through his masterpiece, the Summa Theologica
Quote
“It is necessary to posit something which is necessary of itself, and has no cause of its necessity outside of itself but is the cause of necessity in other things. And all people call this thing God.”
Explanation
Thomas Aquinas presents an argument for the existence of God through the concept of necessity. He suggests that there must exist a being that is necessary in itself—meaning it does not rely on anything else for its existence and has no external cause. This being is the source of necessity for everything else in the universe, meaning that all other things depend on it for their existence. According to Aquinas, this being that is self-existent and the cause of all other existence is what people call God.
This idea forms part of Aquinas’s famous “Five Ways”—arguments for the existence of God, rooted in Aristotelian philosophy and logic. This particular argument is called the argument from necessity. In the world, everything that exists has a contingent nature; it relies on something else for its existence and could theoretically not exist. However, if everything were contingent, then at some point, nothing would have existed, which contradicts the fact that something exists now. Therefore, Aquinas argues that there must be something that exists necessarily—a being that does not depend on anything else and, instead, gives existence to everything else. For Aquinas, this necessary being is God, who serves as the foundation for all other beings.
In modern discussions, Aquinas’s argument invites us to reflect on the concept of causality and existence. His reasoning points to the idea that there must be an ultimate cause or reason behind the existence of everything we observe, something beyond the chain of dependent events. In a universe that seems full of contingent beings—where each thing depends on something else—the concept of a being whose existence is self-contained and who provides the foundation for all existence can be compelling. This argument is meant to bridge faith and reason, inviting believers to consider the logic behind the concept of a self-sustaining cause. Aquinas’s insight remains a significant part of philosophical and theological discourse, providing a foundation for the belief in a divine creator that is at the root of all things.