Chapter 4 : Cosmological Arguments Chapter 5 : Arguments from Design

1. Arguments for theExistence of God Chapter 4: Cosmological Arguments Chapter 5: Arguments from Design

2. Arguments for theExistence of God Fair warning: There will be a quiz later, so take notes.

3. Arguments for theExistence of God Our goal is to evaluate arguments, rather than to use them.

4. Arguments for theExistence of God Our goal is to evaluate arguments, rather than to use them. Keep in mind the difference: Evaluating an argument Evaluating a conclusion

5. Arguments for theExistence of God Even if an argument fails, it’s conclusion could still be true. All of these arguments could fail and their shared Conclusion—God exists—could still be true.

6. Cosmological Arguments

7. Cosmological Arguments A family of arguments (not a particular argument): Appeal to fundamental features of the universe (2) Conclude that God exists

8. Cosmological Arguments Developed by St. Thomas Aquinas, whose aim was to integrate Aristotle’s philosophy into Christian doctrine.

9. Cosmological Arguments Aristotle had the idea of a Prime Mover, a supreme agent that was the first cause of all events and motion in the universe.

10. Cosmological Arguments Five separate arguments for the same conclusion. Aquinas’s “Five Ways” (to prove God exists)

11. Cosmological Arguments Aquinas’s “Five Ways” (to prove God exists) 1) – 4) are cosmological arguments. 5) is an argument from design.

12. Cosmological Arguments Aquinas’s “Five Ways” (to prove God exists) Actually, what all five arguments show is just that a “special agent” exists: an agent that explains certain basic features of the universe.

13. Cosmological Arguments Aquinas’s “Five Ways” (to prove God exists) It remains open whether this “special agent” has the properties of God: -Omniscient -Omnipotent -Loves humans -Cares about human moral behavior

14. Cosmological Arguments Aquinas’s “Five Ways” (to prove God exists) It remains open whether this “special agent” has the properties of God: Aquinas offers other arguments for this (which we won’t read).

15. Cosmological Argument #1: Motion • In the natural world, 1) Objects are in motion. 2) Objects’ motions are always caused by other objects’ motions. 3) Causes must precede their effects. 4) Causal chains of motion must have beginnings. • C) Thus, there must be a “special agent” outside the natural worldwho started the first chains of motion.

16. Cosmological Argument #2: Causality • In the natural world, 1) There are events. 2) Every event has a cause, and no event causes itself. 3) Causes must precede their effects. 4) Causal chains must have beginnings. • C) Thus, there must be a “special agent” outside the natural worldwho caused the first events.

17. The argument from Causality encompasses the argument from Motion. The Causality Arg appeals to events, while the Motion Arg appeals to movement of objects. But the movement of objects is just a specific type of event.

18. Combining Arguments 1 & 2 • In the natural world, 1) There are events/movements. 2) Every event/movement has a cause, and no event/movement causes itself. 3) Causes must precede their effects. 4) Causal chains must have beginnings. • C) Thus, there must be a “special agent” outside the natural worldwho caused the first events/movements.

19. Evaluating Arguments 1 & 2 • Two ways to evaluate deductive arguments: • ? • ?

20. Evaluating Arguments 1 & 2 • Two ways to evaluate (deductive) arguments: • Is the argument valid? • Are the premises true? • Sound argument = ‘yes’ to both questions

21. Arguments 1 & 2: Objection #1 • In the natural world, 1) There are events/movements. 2) Every event/movement has a cause, and no event/movement causes itself. 3) Causes must precede their effects. 4) Causal chains must have a beginning. • 5) Thus, there must be a “special agent” outside the natural worldwho caused the first events.

22. Arguments 1 & 2: Objection #1 • The Birthday Fallacy: 1) Every event traces back to some first event. 2) Every event traces back to a single first event—the same first event.

23. Arguments 1 & 2: Objection #1 • The Birthday Fallacy: 1) Every event traces back to some first event. 1) Every person has a birthday. 2) Every event traces back to a single first event—the same first event. 2) Every person has a single birthday—the same birthday.

24. Arguments 1 & 2: Objection #1 • In the natural world, 1) There are events/movements. 2) Every event/movement has somecause, and no event/movement causes itself. 3) Causes must precede their effects. 4) Causal chains must have a beginning. • 5) Thus, there must be at least one“special agent” outside the natural worldwho caused the first events.

25. Arguments 1 & 2: Objection #1 Even if every natural event ultimately traces back to some supernatural first cause, it doesn’t follow that every natural events trace back to the same first cause. • Is this objection based on truth or validity?

26. Cosmological Arguments 1 & 2 Objection #2: Challenge Premise (2).

27. Cosmological Arguments 1 & 2 Objection #2: Challenge Premise (2). 1) There are events/movements. 2) Every event/movement has a cause, and no event/movement causes itself. 3) Causes must precede their effects. 4) Causal chains must have a beginning. • 5) Thus, there must be a “special agent” outside the natural worldwho caused the first events.

28. Cosmological Arguments 1 & 2 Objection #2: Challenge Premise (2). How do we know that every event in nature has a cause?

29. Cosmological Arguments 1 & 2 Objection #2: Challenge Premise (2). How do we know that every event in nature has a cause? The ordinary events of our experience all have causes, but the beginning of the universe is not an ordinary event.

30. Cosmological Arguments 1 & 2 Objection #2: Challenge Premise (2). This is an inductive inference: The ordinary events of our experience all have causes, so the beginning of the universe must also have a cause.

31. Cosmological Arguments 1 & 2 Objection #2: Challenge Premise (2). This is an inductive inference: But can we generalize from the sample of ordinary events to the events of the universe’s creation? (Are ordinary events a representative sample?)

32. Cosmological Arguments 1 & 2 Objection #2: Challenge Premise (2). The beginning of the universe is not an ordinary event. How do we know events like that don’t have causes, or don’t cause themselves (somehow)?

33. Cosmological Arguments 1 & 2 Objection #2: Challenge Premise (2). Consider our options: 1) Matter simply pops into existence out of nothingness, without any prior cause. 2) Matter is brought into existence by a prior cause, but that cause comes from outside the universe.

34. Cosmological Arguments 1 & 2 Objection #2: Challenge Premise (2). Consider our options: 1) Matter simply pops into existence out of nothingness, without any prior cause. 2) Matter is brought into existence by a prior cause, but that cause comes from outside the universe. Neither of these is anything like ordinary events of our experience.

35. Cosmological Arguments 1 & 2 Objection #2: Challenge Premise (2). 1) There are events/movements. 2) Every event/movement has a cause, and no event/movement causes itself. 3) Causes must precede their effects. 4) Causal chains must have a beginning. • 5) Thus, there must be a “special agent” outside the natural worldwho caused the first events.

36. Cosmological Argument 3 The Argument from Contingency (What’s contingency?)

37. Cosmological Argument 3 X is contingent = X’s existence is contingent upon something else = There is a possible world in which X does not exist.

38. Cosmological Argument 3 X is necessary = X had to exist. = X exists in every possible world.

39. Cosmological Argument 3 1) If every being were contingent, there must have been an “empty time” in the past. 2) If there were an empty time in the past, the universe would still be empty. 3) The universe is not empty. • So not every being is contingent. • Some necessary being—a “special agent”—must be responsible for contingent beings.

40. Cosmological Argument 3 1) If every being were contingent, there must have been an “empty time” in the past.

41. Cosmological Argument 3 1a) Contingent beings now exist. 2a) For every contingent being, there’s some time when it doesn’t exist. 3a) That time is in the past. 1) If every being were contingent, there must have been an “empty time” in the past. If every being were contingent, there must have been an “empty time” in the past.

42. Cosmological Argument 3 1) If every being were contingent, there must have been an “empty time” in the past. 2) If there were an empty time in the past, the universe would still be empty.

43. Cosmological Argument 3 If the universe ever became empty, there would be nothing there to bring new things into existence. 1) If every being were contingent, there must have been an “empty time” in the past. 2) If there were an empty time in the past, the universe would still be empty.

44. Cosmological Argument 3 1) If every being were contingent, there must have been an “empty time” in the past. 2) If there were an empty time in the past, the universe would still be empty. 3) The universe is not empty. • Not every being is contingent. • There must be some necessary being—a “special agent” responsible for contingent beings.

45. Cosmological Argument 3 ✔ 1a) Contingent beings now exist. 1) If every being were contingent, there must have been an “empty time” in the past.

46. Cosmological Argument 3 ✔ 1a) Contingent beings now exist. ? 2a) For every contingent being, there’s some time when it doesn’t exist. 1) If every being were contingent, there must have been an “empty time” in the past.

47. Cosmological Argument 3 ✔ 1a) Contingent beings now exist. ? 2a) For every contingent being, there’s some time when it doesn’t exist. -This might be true of ordinary objects, but is it true of all contingent beings? 1) If every being were contingent, there must have been an “empty time” in the past. -The smallest units of matter (“atoms”/superstrings) could be eternal.

48. Cosmological Argument 3 ✔ 1a) Contingent beings now exist. ? 2a) For every contingent being, there’s some time when it doesn’t exist. 3a) That time is in the past. ? 1) If every being were contingent, there must have been an “empty time” in the past.

49. Cosmological Argument 3 1a) Contingent beings now exist. 2a) For every contingent being, there’s some time when it doesn’t exist. 3a) That time is in the past. 1) If every being were contingent, there must have been an “empty time” in the past. If every being were contingent, there must have been an “empty time” in the past. The Birthday Fallacy

50. Cosmological Argument 3 1) Every contingent being fails to exist at some time. 2) Every contingent being fails to exist at the same time (the “empty time”).