The Five Ways of Aquinas are five philosophical arguments for the existence of God that were put forth by St. Thomas Aquinas in his Summa Theologica. Aquinas used these arguments to provide a philosophical basis for belief in God, and they have been studied and debated by philosophers and theologians for centuries. While there have been criticisms and counter-arguments to each of these arguments, they continue to be influential in contemporary discussions about the existence of God.
- Aquinas’ Five Ways are philosophical arguments for God’s existence based on motion, efficient cause, possibility, gradation, and design.
- These arguments provide a rational basis for belief in God, each addressing different aspects of the universe’s existence and order.
- Aquinas’ arguments remain influential in discussions about God’s existence, despite criticisms and counter-arguments.
The Argument From Motion
St. Thomas Aquinas
The argument of motion, also known as the First Way, is one of the “Five Ways of Aquinas” presented by Saint Thomas Aquinas in his Summa Theologica. This argument is based on the observation that all things in the universe are in motion, and that motion must be caused by something else.
According to Aquinas, everything that is in motion must have been put into motion by something else. He argues that there cannot be an infinite regress of causes, meaning that there must be a first cause that put everything else into motion. Aquinas calls this first cause the Prime Mover, or God.
To understand this argument, it is important to understand Aquinas’ definition of motion. For Aquinas, motion refers not only to physical movement, but also to any kind of change, such as growth or decay. He argues that all things in the universe are in a constant state of change, and that this change must be caused by something else.
Aquinas argues that if something is in motion, it must have been put into motion by something else. He uses the example of a ball being pushed by a stick. The stick is the cause of the ball’s motion, and the ball cannot move unless it is pushed by the stick. In the same way, everything in the universe is in motion because it was put into motion by something else.
Aquinas then argues that there cannot be an infinite regress of causes. If every cause had a cause before it, then there would be no first cause. Aquinas argues that there must be a first cause that started everything else in motion. This first cause, he says, is God.
The Argument From Efficient Cause
The argument from efficient cause, also known as the Second Way, is one of the “Five Ways of Aquinas” presented by Saint Thomas Aquinas in his Summa Theologica. This argument is based on the observation that everything in the universe has a cause, and that there must be a first cause that started everything else in motion.
Aquinas argues that everything that exists in the world has an efficient cause, meaning that it was caused by something else. For example, a tree was caused by a seed, which was caused by another tree, which was caused by another seed, and so on. This chain of causes cannot go on infinitely, because there must be a first cause that started everything else in motion.
Aquinas argues that this first cause is God. He writes that “in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause, whether the intermediate cause be several, or only one. Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate cause.”
In other words, if there is no first cause, there can be no intermediate or ultimate causes. The chain of causes would be like a line of dominoes that never started falling. Something must have started the chain of causes, and that something is God.
The Argument From Possibility And Necessity
The argument from possibility and necessity, also known as the Third Way, is one of the “Five Ways of Aquinas” presented by Saint Thomas Aquinas in his Summa Theologica. This argument is based on the observation that things in the universe are contingent, meaning that they could have not existed or could have existed differently, and that there must be a necessary being that caused all contingent things to exist.
Aquinas argues that everything in the universe is contingent. For example, a tree exists, but it is not necessary for a tree to exist. The tree could have not existed, or it could have existed differently, as a different kind of tree or in a different location. This contingency means that everything in the universe is dependent on something else for its existence.
Aquinas argues that this chain of contingency cannot go on infinitely. There must be a necessary being that caused all contingent things to exist. He writes that “there must be something the existence of which is necessary. Now in the world we find things that are possible to be and not to be, since they are found to be generated and to corrupt, and consequently, it is impossible for all such things to be always. Therefore, we must presuppose the existence of something necessary, which is not from another, but from which all others derive their being.”
This necessary being, Aquinas argues, is God. God is the only being that is necessary, meaning that God exists necessarily and does not depend on anything else for his existence. All other things in the universe are contingent and depend on God for their existence.
The Argument From Gradation
The argument from gradation, also known as the Fourth Way, is one of the “Five Ways of Aquinas” presented by Saint Thomas Aquinas in his Summa Theologica. This argument is based on the observation that things in the universe are measured by a standard of excellence or goodness, and that there must be a being that is the ultimate standard of excellence or goodness.
Aquinas argues that things in the universe can be measured on a scale of goodness or excellence. For example, a good person is better than a mediocre person, and a beautiful sunset is better than an average sunset. This scale of goodness or excellence must have a standard, or a being that sets the standard for what is good or excellent.
Aquinas argues that this ultimate standard of excellence or goodness is God. He writes that “therefore, there must also be something which is to all beings the cause of their being, goodness, and every other perfection; and this we call God.” In other words, God is the ultimate standard of excellence or goodness, and all other things in the universe are measured by this standard.
The Argument From Design
The argument from design, also known as the Fifth Way, is one of the “Five Ways of Aquinas” presented by Saint Thomas Aquinas in his Summa Theologica. This argument is based on the observation that things in the universe are ordered towards a purpose or goal, and that this order must come from a designer.
Aquinas argues that things in the universe exhibit design and purpose, and that this design must come from an intelligent designer. He writes that “things which lack knowledge, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that they achieve their end, not fortuitously, but designedly.” In other words, things in the universe act towards a purpose, and this purpose must come from an intelligent designer.
Aquinas argues that this intelligent designer is God. He writes that “therefore, it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be God.” In other words, God is the intelligent designer that designed and created the universe and all its inhabitants.
