Especially valuable from todays perspective is Aristotle’s doctrine of causes. He spent much time and effort developing it and proposes a categorization of causes in four types. Today we try to explain everything with just one type of cause. With that approach it is very difficult to get an understanding of many aspects of the world. Especially if we want to describe the non-determined, the free aspect of reality. Of course, the attempt to explain everything in a purely deterministic manner must be allowed. But if we demand that everything in the world must be explained with this approach, then we should be able to give a reason for that.
Aristotle writes that all things are made as a union of matter and form, in other words a material and a characteristic layout. Every event, all changes of any object in the world are enabled by four causes. Each of the causes is necessary, and only all four of them together are sufficient for a change to happen. If one of them is missing, there will be no perceivable change. For example, what are the causes for a chicken to hatch out of an egg? First, there is the material that the egg is made of, the material cause. Also, we need it in an appropriate form, here that of a fertilized egg. This is the formal cause. Also, the egg needs to be bred, kept at the right temperature for some time. We call this the efficient cause. At this point, most of the people today would probably conclude their search for causes and declare to be done with it.
For Aristotle however, we have missed one fundamental aspect. For the chick to hatch, there must be the intention to bring another chicken into this world. In case of livestock, a chick will hatch because a farmer keeps chickens. The final cause for the chicken is for example its use for the humans who make their living with it. The final cause is the purpose that something happens for. The reason why it is done. Aristotle claims that not only human actions are motivated by a final cause, but all changes that happen in the world. He differentiates living and lifeless things, and for both their form is essential for the possibilities that they have. But only living things have the possibility to initiate change. The lifeless things cannot create a final cause, they can only get changed by an outside force. This force was ultimately put into motion by a living being. The final cause must be provided by a creatively active being. Without such a being, nothing new can come into existence, and no creative change can happen. That reminds of the words in the bible, describing mankind as a creation after God’s example. Because humans can also provide final causes and be creative, even though they have not yet developed their abilities as much as the first mover, who we can also call God. Mankind only just began to be creative and has a long way to go.
Aristotle is convinced that not only humans follow their intentions, but that the entire world is always and everywhere caused with an intention. He says that it rains for the plants to grow and the rivers to flow. He says the plants grow so we have something to eat. With todays worldview, we accept that we produce a cup so that we can drink from it. We do not drink from cups because they had to be produced in a predetermined consequence of the laws of nature. We had the intention to drink from a cup and that is why we created it. But, in todays worldview, nobody has the intention to let it rain for the plants to grow. We believe that rain is an unwanted consequence of the laws of nature, because the world is as it is. And because of the rain there are plants. And because of the plants there are animals. And because of the animals there are humans. But, following the modern worldview, nobody had the intention to create humans. It all just happened that way. It has no purpose. We lost Aristotle’s final cause.
A reference of an intention focused on the future to a cause at present time, which is completely normal for human actions, is not allowed in modern science. There are laws in physics, no intentions or visions. A cause is always preceding its effect. That is absolutely correct for the efficient cause as described by Aristotle. And physics is responsible for the description of the efficient cause. We should simply avoid to make the mistake of believing that we fully capture the world when only looking at one type of cause.