He went further into his idea and said that knowledge of an object was defined by its causes he said that there were four causes; the material cause, the efficient cause, the formal cause and the final cause. These causes can be defined by a series of questions
What is it made of? We gain knowledge of the object from the material cause by knowing what it is made of, we may understand the limits of rubber for example and therefore by knowing that an object is made of rubber we understand something of its properties. In the case of the chair its material cause would be the wood it is made from, the properties of wood which we already understand, it is strong, supple and hard wearing, can be applied to the chair.
How was it made? The efficient cause gives us knowledge of an object by knowing how and/or by whom it is made. For example if we have a pair of trousers and we know the pieces of cloth have been glued together we will assign different properties to the trousers than if they had been sown together this is because we have knowledge of the two processes and we know that sowing is much stronger. The chairs efficient cause was a skilled carpenter; we now hopefully have knowledge that it will be a solid and well made object we will also understand its limitations.
What does it look like? The formal cause is similar to Plato’s idea of the forms, the formal cause is the form the object takes so that we recognise it. The chair could fulfil all the other causes and not be a chair just a solid lump of wood for sitting on but the formal cause is what leads us to identify it and recognise it as being similar to the last chair we saw.
What is it for? The final cause appears to be the most important cause to Aristotle, it defines the whole purpose of the object and the reason that the other causes ever happened. The chairs purpose is to be sat on and the fact that we sit on chairs is the only reason that all the other causes, The wood, the carpenter and the design, exist at all.
This way of thinking implies that everything is caused by something previous to it, the chair has the carpenter and the wood, the wood has seed and the carpenter has parents but Aristotle rejected the idea of infinite regression, we cannot go backwards infinitely and find more and more causes. He said that we will reach what he called the Prime Mover. This prime mover not only started everything going but was also the end to which everything aims, it was the reason for being. He decided that the Prime Mover must by necessary, perfectly good and eternal.
We can see from these last two paragraphs that the final cause is superior to Aristotle, his idea of the final cause can be paralleled with some of the aspects of the God of traditional theism. The idea that he sources all life gives all things purpose and is an end to which we live our lives to achieve are strongly reflected in the final cause and although Aristotle never implies that the unmoved mover is a being it seems as though to him, this is god.
