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Arguments based on observation Arguments based on reason

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Presentation on theme: "Arguments based on observation Arguments based on reason"— Presentation transcript:

1

2 Arguments based on observation Arguments based on reason

3 What are you most struggling with
What are you most struggling with? Write any questions on your post it note.

4 Round one: Teleological arguments
Group Quiz… Round one: Teleological arguments

5 What is “Teleological argument”?

6 “Telos” = “tail” or “end”
Teleological arguments are often known as design arguments… “Telos” = “tail” or “end” Teleological arguments are those which look at the end results – the world that we can see around us – and use it to draw conclusions.

7 Name 2 philosophers who put forward a teleological argument.

8 Aquinas & Paley

9 Summarise Aquinas’ fifth way.

10 Aquinas, Summa Theologica
“The fifth way is taken from the governance of the world. We see that things which lack intelligence, 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 not fortuitously, but designedly, do they achieve their end. Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God”. Aquinas, Summa Theologica Premise 1 = When you look at the natural world you can see that everything in it follows natural laws, even if the things are not conscious or thinking beings. Premise 2 = If things follow natural laws they tend to thrive and have a goal or purpose. Premise 3 = However, if a thing cannot think for itself it does not have any goal or purpose unless it is directed by something that thinks. Conclusion = Everything in the natural world that does not think for itself heads towards its goal or purpose because it is directed by something which does think. That something we call ‘God’.

11 What is Aquinas’ teleological argument?
Aquinas states that nature seems to have an order and purpose to it… We know, according to Aquinas, that nothing inanimate is purposeful without the help of a ‘guiding hand’ (he uses the example of an archer shooting a target). In other words, no living thing can have its own purpose; the river cannot decide to flow out to the sea because it has no mind, and yet it does. Just like we assume a flying arrow must have been aimed and fired by a person, we can assume that there must be something (a ‘guiding hand’) behind the purposiveness of the inanimate objects around us. Aquinas concludes that the guiding hand behind this is God. Everything in nature that has no intelligence must be directed to its goal by God.

12 Summarise Paley’s design argument.

13 From a complex object of many parts, containing the qualities of regularity and purpose, we may infer that it was designed. The world and its contents are complex, and of many parts, containing the qualities of regularity and purpose. We may therefore infer that the world was designed. CONCLUSION: the world has a designer - God

14 Thomas Aquinas: The Archer William Paley: The Watchmaker
Aquinas believed that everything in the universe has a purpose and that this purpose is given to it by God, just as the arrow flying through the sky is given its purpose by the archer who fires it. It was the 5th of his 5 ways of showing the existence of God William Paley: The Watchmaker Paley believed that just as watches, which exhibit complexity and purpose in order to tell the time for us, have watchmakers, the world, which has complexity and the purpose of sustaining life has a world maker; God.

15 How does Hume criticise teleological arguments?

16 Aptness of analogy (We wouldn’t think a cabbage had a cabbage maker if we came across it…how is the world any more like a watch than it is a cabbage/ a dandelion…by choosing a machine as their analogy (watch), thinkers like Paley have already determined the result that they want). The Epicurean thesis (in infinite time there will likely be a time when things fit together in a good combination…so perhaps stable order could appear at random, without the need for a designer). Argument from effect to cause (we cannot go from an effect to a cause greater than that needed to produce the cause) Green book – pages 62-63

17 How does Mill criticise teleological arguments?

18 Mill points to the amount of evil in the world…from a flawed universe, the most we can infer is a flawed creator.

19 How could the work of Darwin be used to criticise teleological arguments?

20 Evolution points to a world where survival is a matter of pure chance and it questions design…

21 Round two: Cosmological argument
Group Quiz… Round two: Cosmological argument

22 What is a Cosmological Argument?

23 In other words, it rejects the idea of an INFINITE REGRESS of causes.
An a posteriori argument for God’s existence which starts from the fact that the universe exists. It claims that the universe was caused to exist by something that was itself uncaused. In other words, it rejects the idea of an INFINITE REGRESS of causes. What is an infinite regress? Infinite = never ending. Regress = going backwards. ‘Infinite regress’ refers to the idea that there is no beginning, no first cause, we just keep going back further and further, never reaching an end point. Again the Cosmological Argument rejects this. A Posteriori Infinite Regress? ‘Infinite regress’ refers to the idea that there is no beginning, no first cause, we just keep going back further and further, never reaching an end point. An argument based on the idea that things can be proved based on experience.

24 What is Aquinas’ Cosmological Argument?

25 Thomas Aquinas’ Five Ways
The Five Ways are arguments created to prove the existence of God. Found in Aquinas’ influential work on Christian theology the Summa Theologica. The first 3 of the Ways are collectively known as the Cosmological Argument; Motion/Change (PRIME MOVER) Causation (FIRST CAUSE) Necessity (NECESSITY & CONTINGENCY) Each Way points to observable evidence

26 1. The argument from motion - God as the first mover / unmoved mover / Prime Mover
We observe that some things in the world are in motion Whatever is in motion is put into motion by another object that is in motion This other object was put into motion by another object before it, and so on This cannot go on backward to infinity because there would be no first mover and so no subsequent movement Therefore, we must conclude that there is a first unmoved mover, which we understand to be God

27 2. The argument from causation - God as the first cause / uncaused causer
We observe that everything has a cause We also observe that nothing can be the cause of itself It is impossible that the series of causes should extend back to infinity because every cause is dependent on a prior cause So if there is no first cause, there will be no intermediate causes and no final cause We observe causes so there must be a first cause, which everyone calls God

28 3. The argument from necessity - God as the necessary being (on which contingent beings rely)
We observe things that come into and pass out of existence - they are contingent If it is possible for everything not to exist, then, at some point, nothing existed If nothing ever existed, then nothing would exist even now, since everything that exists requires for its existence something that already existed But clearly things exist now Therefore, not all beings are contingent, there must be something that is necessary to cause contingent things This necessary being is called God

29 How does Leibniz try to improve Aquinas’ Cosmological Argument?

30 Gottfried Leibniz (1646-1716) Tried to improve on Aquinas’ third way…
Leibniz raised the question “Why is there something rather than nothing?” In order to address this question he offered a form of cosmological argument, which he based on his PRINCIPLE OF SUFFICIENT REASON.

31 The principle, which is not universally accepted, states that everything that exists must have a reason or a cause for its existence. The basic idea behind the principle is this: Take any feature of the world. If the world could have failed to be that way, then there must be some explanation of why the world is that way. So, for example, we might notice that although the sky is blue, it might not have been - the sky on earth could have failed to be blue. Given only this, Leibniz concludes that there must be some reason, or explanation, why the sky is blue: some reason why it is blue rather than some other colour. According to the Principle of Sufficient Reason: If something exists, there must be a reason why that thing exists If a statement is true, there must be a reason why that statement is true If something happens, there must be a reason why that thing happens

32 How does Russell argue against Leibniz’s Cosmological Argument?

33 Russell states that Leibniz is guilty of a logical fallacy…
Green book – pg 73

34 Round three: Ontological argument
Group Quiz… Round three: Ontological argument

35 What is an Ontological Argument?

36 The ontological argument is an a priori, analytic proof for the existence of God.
According to the ontological argument, almost everything (with the exception of God) which exists, does so in a contingent way; it depends upon other factors. God is not a ‘thing’; unlike everything else God has not come about because of anything; there was no time when God did not exist, and there is nothing that could cause God to cease to exist.

37 What is St Anselm’s Ontological Argument?

38 Anselm's first ontological argument:
1. God is the greatest possible being which can be conceived of 2. God may exist either in the mind alone or in reality as well 3. Something which exists in reality and the mind is greater than something that exists as an idea in the mind alone 4. Therefore God must exist in reality and the mind and the concept of God is surpassed by an actual, existent God.

39 Anselm's second ontological argument:
Anselm’s essential claim is… Existence is a predicate of God (it is a property or quality of God’s nature). God is that than which nothing greater can be thought… Because God is unsurpassable in every way, God must have necessary existence. Therefore God exists – Necessarily (Existence is a predicate of God)

40 How does Gaunilo criticise St Anselm’s Ontological Argument?

41 Gaunilo suggests that Anselm’s views on God existing necessarily were unintelligible. He suggests that the fool that Anselm quotes from the Psalms could respond in the following ways: Gossip: The fool may have in his mind all sorts of things that don’t exist. You could hear about someone through gossip but it doesn’t necessarily make it true. Defining things into existence: Gaunilo argues that you cannot define an idea into existence. Just because you have an idea it doesn’t follow that it exists. Philosophers in the Middle Ages said that you cannot PROVE from what is said (de dicto) what exists in reality (de re) Gaunilo’s Island: The most famous example from Gaunilo is his perfect island.

42 Gaunilo’s Island… You can have a clear idea of a perfect island, but that does not mean that it exists. Anselm can't prove that the idea of God as the greatest possible being means God exists in reality

43 How does Gaunilo criticise St Anselm’s respond to Gaunilo’s Island?

44 Anselm was impressed with Gaunilo’s argument and he replied to it.
Anselm’s response… Anselm was impressed with Gaunilo’s argument and he replied to it. Anselm said although Gaunilo was right in terms of the Island, the same objection did not work when the ontological argument was used of God – this is because the Island has contingent existence, whereas the existence of God is necessary. The ontological argument ONLY WORKS when it is applied to GOD and the unique way in which he exists; that’s the whole point of the OA.

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46 How does Descartes develop St Anselm’s Ontological Argument?

47 Descartes defines God as 'a supremely perfect being' From this point, he tries to prove God's existence. 1. God is a supremely perfect being 2. A property of perfection is existence - existence is a predicate 3. Therefore, God exists

48 How does Kant criticise Descartes?

49 Kant says “Existence is not a predicate
Kant says “Existence is not a predicate!!!” - We can have an idea of what a unicorn is, but this does not mean it exists in reality, even if a predicate for it is that it is living - All philosophical ideas are synthetic according to Kant - they need to be verified.

50 What are a priori & a posteriori arguments?

51 A posteriori arguments – arguments which draw conclusions based on observation through experience. A priori arguments – arguments which draw conclusions through the use of reason.

52 Are a priori or a posteriori arguments most convincing?

53 Find out the answer to the question you have been given
Find out the answer to the question you have been given. Be ready to teach it to the rest of the class…

54 Arguments based on observation Arguments based on reason

55 Create a revision poster…
Split your page into 3. Teleological Cosmological Ontological Summarise key philosophical views and the criticisms of these. Can you include key terminology? Can you include quotes? Extension: Which arguments are the most convincing and why? Which arguments are the least convincing and why?

56 Write any questions on your post it note.


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