explain Aristotle's theory of the four causes

Aristotle was an empiricist, and believed that we gain our knowledge of the world from what we experience by using our senses. He rejected Plato’s’ idea that true knowledge exists in the empirical world and that two different realms existed. He said we live in a spacio-temporal world in which we can find true knowledge as it’s though our experience that we can come to understand things.  Aristotle believed that as there is no evidence for the existence of the world of the Forms, it doesn’t exist and therefore we can only really know about this world as we can use our senses to gain reliable facts about it.

Aristotle looked at the world around him and asked what does it mean for something to ‘exist’ and what gives particular objects their characteristics. Although he was a pupil of Plato’s, he didn’t follow the Platonic route of abstract Forms of objects. He believed that the form is the structure and characteristics of objects and can be found within the actual object itself.  From this, Aristotle explains how the forms can be seen and discovered to humans by the use of the senses.

   Aristotle talked about two states of being: potentiality and actuality. He used these terms to explain the possibility of doing something and when it is actually achieved. Although many objects have the potential to become or do something, not all will achieve its potential. Just because there is potential, does not mean it will definitely be actualised. Aristotle said that something needs to happen to cause things to change from potentiality to actuality as he believed it cannot happen on its own.

To explain the movement from potentiality to actuality, he came up with a chain of causes to explain how things are. He decided that the explanation of things could be seen in four different ways, at four different levels. He called these the four causes. The first Cause that Aristotle came up with was the Material cause. This answers the question ‘what is the material or matter than an object is made of?” Aristotle used the example of bronze and silver as examples of the material cause. He explains how a statue is made of bronze and therefore the material cause of the statue is bronze as it is needed in order to produce the statue. The bronze is a subject of change because it undergoes changes in order to result in the statue. Objects however may contain more than one material cause, such as a chair, as it may be made of a component of materials such as wood and metal. Without these elements, the objects wouldn’t exist.

Aristotle then discovered the Efficient Cause. This is the way in which the object came to being, the way in which an object was created. Had there not been an efficient cause, these objects would not exist as something causes it to be. This efficient cause might be an agent or a natural phenomenon.  To continue Aristotle’s sculpture idea, the efficient cause would be the way in which the bronze was moved from its state of potentiality to becoming the actual statue. A sculptor would be the efficient cause. 

The next cause is known as the Formal Cause. This cause explains the kind of thing that it is. This cause looks at the shape of which the material of the object has. If it were not that shape, then it would not be the object. For example, the formal cause of a statue might be that is has the characteristics of a statue or the pattern that the sculptor followed. It is no longer just a lump of material such as marble or bronze that someone has picked away it: it looks like something specific such as a person. The formal cause is the Form that it conforms to and answers the question, ‘What are its characteristics?’

The fourth cause, the Final Cause is seen as the most important out of all the causes that Aristotle came up with. The Final Cause is the aim for which an object is created. It is the purpose for why something exists and what it is for. The Final Cause of the statue is that the sculptor wanted to make a beautiful object for decoration or for some other purpose. Aristotle would say that the sculptor set out with an aim in mind. 

Aristotle believed that all objects have an ultimate reason for their existence and that all nature has a purpose. Aristotle believed that the Final Cause gives the best explanation of an object. The final end or purpose: the teleology of a thing when realised gives that thing its full perfection and reality. When something is doing what it is supposed to be doing, Aristotle would say that it had achieved goodness. To him, the purpose of an object is intrinsic; it’s not something that we can choose to impose on it. From this thought, looking at the bigger picture, Aristotle thought that the universe as a whole has a purpose too. 

Although Aristotle said that everything is caused by something else, he doesn’t believe in infinite regression and states that the chain of cause and effect cannot go on forever. He argues that there must be a thing that started it all without itself being caused. Change has always been occurring as it is eternal. There can’t have been a first change as something would have had to happen to start that change and this is a change in itself and so on. In Metaphysics, Aristotle says ‘There must be a mover which moves them (stars etc) without being moved, eternal and a substance and actual.’ Here Aristotle came up with the idea of the Prime Mover. The Prime Mover is motionless, unmoved and is the necessary first source of movement as it doesn’t rely on anything else for existence. It is a pure substance that has no form. The final cause behind everything is the Prime Mover; this is why it is the most important cause of all.

To conclude, Aristotle's belief that nature does not act without a purpose, there is purpose within nature (teleology) became very important to him and he developed his notions of the concept of cause and effect in the Metaphysics. His four causes of an object and the Prime Mover became central to all of his work that followed as the prime mover became Aristotle’s idea of God, not one that people can pray to or have a relationship with but one that represents the end to which all matter is moving and aspiring.