Aristotle. Cause, Purpose and the Prime Mover

Transcription

1 Aristotle Cause, Purpose and the Prime Mover Aristotle Dates: BCE Books: Physics, Metaphysics, Nicomachean Ethics Taught by Plato from age Left Athens when he was not appointed head of Plato s academy on Plato s death Tutored Alexander the Great Returned to Athens and set up rival academy called the Lyceum We need to look at Aristotle s work in his Metaphysics book 12. ( Metaphysics means after physics ) Aristotle, the first real scientist, examined the nature of reality, as did Plato. However, Aristotle saw reality in a very different way from Plato. Plato, remember, separated existence into two areas: The Forms: The visible world: These are true reality. They are perfect, eternal, unchanging. These are poor copies of the forms. They are imperfect, finite and they change. Plato regarded the Forms as the ultimate reality. The things in the visible world get their characteristics by participating in or sharing something from the Forms. e.g. if I carefully draw a triangle on the board, it still won t be a perfect triangle, yet you will recognise it as a triangle. Our minds somehow know the Form of a triangle. My scrappy drawing of a triangle will cease to exist, but the Form Triangle will always exist. The Forms do not exist in our world, but in another dimension that is nevertheless accessible to our minds (via our eternal souls Plato says).

2 Aristotle saw the world very differently. Our world is reality, not a shadow or copy The Forms are part of things in our world, not separate e.g. The Form of the pot shapes the clay the Form of the pot exists in the pot it is what makes it a pot. Compare Plato s and Aristotle s understanding of a clay vase: Draw your own vases! Plato explains the shape Aristotle explains the shape of the vase by of the vase by Aristotle was also unhappy with the idea that the Forms are unchanging and eternal, since they do not explain why things on earth do change. Aristotle explained change in terms of potentiality and actuality. e.g. the wood is a potential chair and an actual tree the person is a potential university graduate and an actual sixth-former The boy wizard Harry Potter already has within him the potential of being a man wizard. Everything around us changes - from the weather to our physical appearances as time passes - and all these changes are caused. The aim of science is to state just what these causes in our environment are and explain how they do their 'job'. As we might expect of a proto-scientist like Aristotle his writings are full of his own understanding of how these causes do their thing.

3 This is what he actually says: "A thing is a called a cause in one way if it is a constituent from which something comes to be (for example, bronze of the statue, silver of the goblet).... in another way if it is in the form and pattern, that is, the formula of its essence, and the genera of this (for example, 2:1, and in general number).... again, if it is the source of the first principle of change or rest (for example, the man who deliberates is a cause, and the father of the child, and in general the maker of what is being made and the changer of what is changing); again, if it is a goal - that is, that for the sake of which (for example, health of walking - Why is he walking? - we say: 'In order to be healthy', and in so saying we think we have stated the cause) For Aristotle, causation can be sub-divided into four types - the so-called "Four Causes". The Four Causes - An examination of each type Try to keep in mind is that for Aristotle to ask for the cause of something is to ask for the because of which. Aristotle s Four Causes His four causes are: Material Cause what something is made of, e.g. wood, human tissue Formal Cause what makes it what it is (its form), e.g. the design or plan Efficient Cause what acts upon something to make it what it is, e.g. a sculptor chisels the stone Final cause The purpose or reason for its existence, e.g. statue to remember a hero

4 Let s look at each cause in more detail: Material Cause - what is it made of? The first cause is the constituent from which something comes to be. Aristotle calls this type cause as matter, but these days it's called the "Material Cause". e.g. "bronze of the statue" is a material cause in the following way: The cause of the statue being heavy / malleable / difficult to move etc. is because it is made of bronze. The bronze, being the constituent stuff of the statue, is therefore the statue's material cause according to Aristotle. Since this material has the potential for change, e.g. wood can burn, bronze can melt, it is the material cause which gives objects in our world the impermanent. Formal Cause What are its characteristics? Aristotle's second sort of cause, what he calls "the form and pattern", is usually referred to as the "Formal Cause". This is kind of odd in that the 'what-it-is' and the 'why-it-is' are the same thing! It is the formal cause that allows us to recognise the object for what it is. Having the form and pattern that includes: trunk, grey skin, and tusks is what allows us to recognise the object as belonging to the category elephant. Try to identify the form of object that the following: Paper pages, hardened covers, ink stamped on the pages Formal cause of a Four wooden legs, flat top, backrest Formal cause of a Wacky unfashionable clothes, too much makeup, listens to terrible music Formal cause of a

5 Efficient Cause How does it happen? The third type of cause is the one most modern readers tend to think of when considering causation (i.e.) the action of one thing upon another pushings and pullings. The third type is called the "Efficient or Motive Cause". The efficient cause may be a person, e.g. a sculptor, painter etc. However, it may be a process (photosynthesis), a natural phenomenon (a lightning bolt) Efficient causes seem to be distinct from the 'objects' that they operate upon e.g. the father (efficient cause) is distinct from the son, whereas the bronze (material cause) is not distinct from the statue. Final Cause what is it for? Aristotle calls his fourth cause that for the sake of which or the goal. It is usually known as the Final Cause. The normal way of expressing the way the final cause works is to use the connective "in order to" or "in order that". This is the most important cause for Aristotle. e.g. Why does she walk? In order to be healthy. Thus, the 'cause' of her walking is the wish or desire to be healthy. With tables and hammers, etc, what they are for is usually quite clear. The final cause is: The final cause is: The final cause is: However, what is the final cause of a fish? A germ? A slug? A human? The germs goal may be simply to reproduce. The fish s final cause may be to swim and reproduce.

6 When it comes to humans we need to know what a human is for, what our purpose is. Aristotle wants to know what the telos (purpose/end) for which a thing exists is (remember the teleological argument). If something achieves it purpose or does well what it is for, then it is a good thing. So a cancer that spreads quickly, for Aristotle, is a good cancer it performs its function well because it is for spreading! Final causes are different from the other causes: final causes come after their effects. In Aristotle's example, health is offered as the cause of the walking yet it comes about after the walking has happened. final causes may be effective without ever existing! Think about it, health may be the final cause of Agnes' walking but she may never get to be healthy (i.e.) her health never exists because she is run over and killed whilst out trying to get walking-related health and fitness. e.g. "Why does Agnes walk?" "For health." That is, health is her goal and health is achievable by walking. e.g. "Why do ducks have webbed feet?" "For swimming" That is, swimming is a 'goal' for ducks. To put it another way, it is good for ducks to swim; and swimming is made easier by having webbed feet. Aristotelian change and causation on a world-wide scale In Aristotle's world-view the natural world is a world of regularity and identifiable patterns, but it is also a world of continuous change. But how is all this regularity and change organised? Are there gods to keep it all going? Outwardly, Aristotle was a conventional polytheist (many gods). However, it appears that this was a socially acceptable facade. In book VIII of the Physics, Aristotle argues for the existence of a changeless source of change - an "unmoved mover". The "unmoved mover" must be beyond the universe or else it too would require a cause of its motion reasoned Aristotle.

7 The common interpretation of all this Aristotelian talk about gods and divine movers is that it is not realist but metaphorical, not unlike Einstein's use of 'God' in his physics. But if Aristotle's prime mover is only the personification of an ultimate inanimate causal principle, the question remains to be asked of Aristotle exactly what this unmoved mover is and how it operates. Let s try applying Aristotle s four causes. For each of the following, state the different causes: Material Cause: Formal Cause: Efficient Cause: Final Cause: Notice how the first two types of causes explain how the object is the way it is at the present moment. The second two types explain why the object came to be as it is. Material Cause: Formal Cause: Efficient Cause: Final Cause:

8 Material Cause: Formal Cause: Efficient Cause: Final Cause: Easy so far? With manufactured objects it is fairly straightforward. Let s try it with natural objects: Material Cause: Formal Cause: Efficient Cause: Final Cause: Fur, protein, skin, bone, etc. Four legs, wagging tail, form of a dog Internal development, genes To bark, wag tail do dog things Material Cause: Formal Cause: Efficient Cause: Final Cause: Material Cause: Formal Cause: Efficient Cause: Final Cause:

9 Purpose For Aristotle, everything has a purpose and a function (ergon). A good example of a particular thing is one that fulfils its function well. Purpose is the fourth of Aristotle s four causes, for example, the purpose of the pencil is to write with this is why it was made and if it writes well, it fulfils its purpose well, so it is a good pencil. For natural objects the same applies. The purpose of each is to perform well what that natural object is for (which is often what it usually does), for example the purpose and function of a bird is to fly, to nest, to reproduce. This also works with parts of natural objects. The purpose of an ear is to The purpose of a nose is to St Thomas Aquinas Natural Law theory is based on Aristotle s teaching. Aquinas said that each part of your body has a specific function and should not be used for anything else (no smirking at the back!). You can consider the functions of your body at your leisure! What is the function or purpose of a human? It cannot just be to reproduce or we are no different than a rabbit, and there is no point in you being in here right now, you might as well be out in the fields with the other beasts reproducing! To be a good human we need to know what the purpose of a human is so we can perform that function well. So what is the purpose of a human? We should note here that Aristotle is not claiming that nature has a purpose and that we are a part of it. Aristotle is claiming that individual things in nature have individual purposes. Each thing in nature has an end (telos) towards which it works. That end is suited to the type of things that objects are. We are thinking, reasoning things, so our end / telos will be related to this aspect of our nature.

10 Aristotle s Prime Mover Aristotle believed that there was a common source of all things that explained how all things began. This common source of all things must be an eternal thing that does not change, otherwise it would also require a source of its existence and a source of its change (similar to Aquinas First Cause argument!). Aristotle refers to the common source as the Prime Mover God in other words. Aristotle is not saying that the Prime Mover pre-existed the universe and that the universe had a beginning, caused by God. Rather, Aristotle is saying that all things depend on the Prime Mover. We can note some other concepts that apply to Aristotle s Prime Mover: Unmoved Mover: The Prime Mover does not move other things because it itself is moving that would imply God changes and God cannot do that. Rather, The Prime Mover is pure, continual and eternal thought and it is this continual thought that the universe is influenced by. The universe, the planets, life on earth, all reflects God s eternal movement of thought. All life and change depends on God, but God takes no action to cause it. Life is rather drawn towards God. Pure Actuality: Aristotle saw change as being from potential to actual. Since God cannot change, the Prime Mover contains no potentiality, only actuality. In this sense, God is pure actuality. Immaterial: Since matter is potential (it changes from potential to actual, e.g. wood is potential fire), and God has no potentiality, God cannot be matter. The Prime Mover is totally immaterial (non-physical). So the Prime Mover cannot move anything physically things are just drawn towards the Prime Mover, influenced by God. Not a Creator: Aristotle believed that the Prime Mover influenced all things, but he also believed that matter had always existed. So Aristotle s God is not a creator ex nihilo (created all things out of nothing), as the Judaeo-Christian God is said to be.

11 Disinterested: The Prime Mover is concerned only with what is perfect, so is self-contained as only it is perfect. The Prime Mover is not interested in the world, nor is even aware of it. Aristotle s God is therefore completely disinterested in our world. Our world is merely sustained by God s existence. It must be of itself that the divine thought thinks (since it is the most excellent of things), and its thinking is a thinking about thinking Aristotle, Metaphysics, Book XII How does Aristotle s Prime Mover compare with the Judaeo-Christian God? Aristotle s god Judaeo-Christian God Unmoved Mover Pure Actuality Immaterial Not a Creator Disinterested Criticisms of Aristotle The Material Cause is just seen as what it obviously is, e.g. wood, metal, etc. which leaves no room for analysing the material cause any further. Today we might say the wood is made up of The Aristotelian idea of change, from potentiality to actuality, with the potential contained within, does not sit well with modern thought. Today we would account for change within a thing in terms of

12 Aristotle s Final Cause does not fit in with modern thinking about how things come to be. How would evolution assess the Final Cause of an emu s wings? Aristotle said that nature does nothing without a purpose or uselessly How would Aristotle account for the Final Cause of the emu s wings? With regard to the Prime Mover, we could ask a number of questions (many of which we would also ask of the Cosmological Argument). If the Prime Mover is the reason everything else moves, what moved the Prime Mover? To say that the Prime Mover is a special, unique case is not enough. Surely then we could ask why there are not other Prime Movers. In fact, Aristotle at times suggests there may be other Prime Movers, but the question remains as to how the unmoved mover started moving. In common with criticisms of the Cosmological argument, we can refer to Newton s First Law of Motion: An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force. How is this a criticism of the idea of the Prime Mover? Conclusions: We can clearly see that there are problems with Aristotle s approach to explaining cause, purpose and the Prime Mover. His approach seems outdated today and raises perhaps as many problems as it solves. However, his four causes provide a useful framework for the consideration of things in the world that encourage us to look beyond the obvious. In this way, Aristotle has made a significant contribution to the development of modern science. Aristotle was a massive influence of the work of Thomas Aquinas, particularly his Five Ways of proving God s existence and Aquinas Natural Law theory. Since Natural Law is still the official moral theory of the Catholic Church today, Aristotle s philosophy is still significant today.