1. René Descartes (1596-1650 AD) Meditations on First Philosophy (1641) (Text, pp. 87-119)

3. Descartes’ Problem l The problem of skepticism (D concentrates on 2 types of skepticism) –General skepticism: There are NO indubitable beliefs or propositions. –Skepticism concerning the existence & nature of the “external world”: The existence and nature of the “external world” cannot be known. Background

4. The overall structure of D’s Meditations (next slide)

5. GeneralCogito (existence of the “I”) (Med. I) (Med. II) Mind-Body Dualism Skepticism God (no deceiver) External 1. My idea of God (III) World 2. My contingent (Meds. III-VI) existence (III) 3. The ontological argument (again) (V)

6. Meditation I Radical (General) Skepticism (Text, pp. 87-92)

7. Descartes’ “Foundationalism” (See Text, 87-8)

8. D’s program of radical doubt l Treat any belief that is to the slightest extent uncertain & subject to doubt just as though it is obviously false. l Accept only those beliefs that are completely certain and indubitable. l Work on the foundations of my beliefs. (Text, 88)

9. Foundational Beliefs l Empiricism: True beliefs are acquired through sense experience (89). l My beliefs are not products of insanity (89). l My beliefs are not products of my dreams (89-90).

10. Foundational Beliefs, cont’d l Physical objects: Even if we fail to perceive physical objects accurately, the “primary [measurable] qualities” of such objects (matter, extension, shape, quantity, size, location, time, etc.) are really real (i.e., physical objects do really exist) (90-91). l Even if empirical beliefs are subject to doubt, mathematical propositions are indubitable (e.g., 3 + 2 = 5, a square has neither more nor less than four sides) (91).

11. l How does Descartes challenge each of the foregoing foundational beliefs? l How does he use the ideas of God and the Devil in building his case in support of radical skepticism? (Text, 91-92)

12. Meditation II Descartes’ Refutation of Radical Skepticism (Text, pp. 93-97)

13. Descartes’ refutation of radical skepticism “Cogito ergo sum!” What does this mean?

14. The most famous statement in the history of philosophy: “I think; therefore I am.” Discourse on Method (1637)

15. “If I am deceived, then I must exist!” I cannot doubt the truth of the statement, “I exist.” (Text, 93-94)

16. Thus, Radical (general) skepticism is refuted.

17. Meditation II, cont’d The Mind-Body Problem & Descartes’ Psycho-Somatic Dualism (Text, 94-97)

18. Three metaphysical perspectives relevant to the “mind-body problem”

19. Metaphysical Dualism: Reality is two- dimensional, partly material and partly non- material (minds, ideas, souls, spirits, consciousness, etc.). Metaphysical Materialism: Reality is nothing but matter-in-motion-in-space-and-in-time. There are no non-material realities. Metaphysical Idealism: Reality is nothing but Mind, Idea, Soul, Spirit, Consciousness, etc. Matter does not exist (it’s an illusion?).

20. Application to the “mind-body problem” l Metaphysical Materialism: A person is nothing but a physical organism (body only). l Metaphysical Idealism: A person is “consciousness only” (mind, soul, spirit); not at all a material being. l Metaphysical Dualism: A person is a composite of (1) “mind” (consciousness, soul, spirit) and (2) body.

21. Cartesian Dualism l I know with certainty THAT “I” exist (Cogito ergo sum), but l WHAT am “I”? l Am “I” my body? No, because I can doubt the existence of my body, whereas I cannot doubt the existence of myself (the “I”). l “I” am a thinking thing, a thing that doubts, understands, affirms, denies, wills, refuses, imagines, and has sensations.

22. Is Descartes right? Can you doubt the existence of your body (as well as other physical things)? Why or why not?

23. “I can conceive of myself as existing without a body, but I cannot conceive of myself as existing without conscious awareness.” Bryan Magee, The Great Philosophers (Oxford 1987)

24. In Descartes’ view, my body exists (if it exists at all) outside of my consciousness and is therefore part of the “external world.” Thus,

25. Descartes’ mind-body dualism leads to....

26. Meditation III, which deals with (1) skepticism concerning the existence & nature of the “external world” & (2) the existence of God (Text, pp. 97-110)

27. “I must, as soon as possible, try to determine (1) whether or not God exists and (2) whether or not He can be a deceiver. Until I know these two things, I will never be certain of anything else” (Text, 99). Why does Descartes say this?

28. Descartes’ standard of certainty l What does it take for a belief to be certainly (indubitably) true? l The belief must be “clear and distinct.” l Descartes’ general rule: “Everything that I can clearly and distinctly grasp is true.” (Text, 98)

29. Are the following beliefs “clear & distinct” (indubitable) ? l That there are things outside myself (such as physical objects). l That these external things cause my ideas of those things in my mind. l That my ideas of external things perfectly “resemble” the things themselves. l That 3 + 2 = 5 ? (Text, 98-99)

30. Reasons for believing (1) that there are things outside myself (2) which cause my ideas of those things in my mind and (3) that my ideas of external things “resemble” (accurately represent) the things themselves*: *The epistemology represented by (1), (2), & (3) is known as “Common Sense Realism” or “Representationalism.”

31. I have a strong natural inclination to believe these things. My ideas of external things arise in my mind independently of my will. It seems obvious that external objects impress their own likenesses upon my senses. (Do these reasons “clearly & distinctly” prove that Common Sense Realism is true?) (See 100) (Text, 99-100)

32. Ideas & their causes (Text, 101-105)

33. When I think of an entity, I can distinguish between.... l Substance (i.e., the entity itself, e.g., an automobile tire), l Modes (i.e., the ways in which the entity exists, e.g., the tire may be flat ), and l Accidents (i.e., the properties, qualities, or attributes of the entity, e.g., the color of the tire [blackness?] ). And isn’t it obvious that substance is more real than mode or accident? (Text, 101)

34. Ideas of things (substances, modes, accidents) must be caused to be in the mind, and the cause of any effect must be sufficient to produce its effect, i.e., there must be at least as much reality in a cause as is represented in its effect. (Text, 101-103)

35. Descartes thinks of ideas as l subjective representations of the realities that cause them to be in the mind (102). l He also believes that ideas cannot represent more reality (anything greater or more perfect) than is in the things the ideas represent (102-3). l But is this last point true? Suppose I perceive an automobile with a dented fender &, from my perception, an idea of the car arises in my mind. Why can’t I think of the car as NOT having a dented fender? l How might Descartes respond to this criticism?

36. If one of my ideas l has something in it that is not within myself, then l I could not be the cause of that idea; whereas l if I could be the cause of all of my ideas, then l I will have no foolproof reason to believe that anything exists other than myself. (Text, 103)

37. Ideas in my mind: l of myself (could be caused by myself) l of God l of lifeless physical objects l of angels l of animals l of other people Could be composed from my ideas of myself, physical objects, and God (how?) What about physical objects? (Text, 103)

38. The qualities of physical objects: l Primary qualities: size, length, breadth, depth, shape, position, motion, substance, duration, number, etc. l Secondary qualities: light, color, sound, odor, taste, heat, cold, etc. (Text, 103-104)

39. Since my ideas of the secondary qualities of physical objects l are not “clear and distinct,” l and since such qualities are almost indistinguishable from nothing (i.e, they seem to represent very little reality), l I myself [a substance] could be the author of such ideas. (Text, 104)

40. I could also be the cause of my ideas of primary qualities. l I am a substance. l I have duration in that I exist now and have existed for some time. l I can count my several thoughts and thus the idea of number may be grounded in my thought process. l But what about my ideas of extension, shape, position, and motion? (Text, 104-105)

41. Although extension, shape, position, or motion do not exist in me (since “I” am not a physical being), these are only modes of existence, and, as a substance, “I” have more reality than these modes and “I” am therefore sufficient to cause my ideas of them. (Text, 105)

42. Thus, I could be the cause of my ideas of both the primary and secondary qualities of physical objects. However,

43. I do not have what it takes to produce the idea of God (an infinite substance) from within myself (a finite substance).

44. Descartes’ first argument for the existence of God.... (Text, 105-107)

45. “By ‘God,’ I mean an infinite and independent SUBSTANCE, all-knowing and all- powerful, who created me and everything else.... ” (Text, 105) This idea represents more reality than there is in myself (since I am finite, limited in knowledge & power, etc.). Thus, the idea of God must be caused to be in my mind by something other than myself. And....

46. since there must be at least as much reality in a cause as there is in its effect(s), it follows necessarily that my idea of God must be caused by God Himself; and if God is the cause of my idea of God, then God must exist!

47. Descartes’ main point here is l that I could not be the cause of the idea of God that I find in my mind l since God is a being more perfect than myself. l How could I, merely from within myself, form the idea of a being more perfect than myself? l Then my idea would represent more reality than there is in its cause. Only God is a sufficient cause of the idea of God in my mind.

48. Descartes’ second argument for the existence of God.... (Text, 108-110)

49. I exist as a thinking thing with the idea of God (an infinitely perfect being) in my mind, but my existence is not necessary -- it is contingent -- which means that I must be caused to exist (at every moment of my existence) by something other than myself (108-9).

50. If the cause of my existence l is itself a contingent being (e.g., my parents or something else less perfect than God), then l it must also be caused to exist by something other than itself. But.... l this cause-and-effect process cannot go on to infinity since in that case l I could never begin to exist. l So.... (See Text, 109)

51. there must be a First Cause whose existence is necessary (rather than contingent). Furthermore..., (Text, 109)

52. this necessarily existing First Cause, l which is the ultimate cause of my existence, l must have the idea of God in it, and l since it is a First Cause, its idea of God must be caused by itself and nothing else, which means l that this First Cause must be God (since only God can be the original cause of the idea of God in any mind). (Text, 109)

53. Why does Descartes reject the claim that his existence as a contingent being with the idea of God in its mind might be the effect of several natural causes, each representing a different kind of perfection? (See Text, 109-110)

54. Conclusion of the 3rd Meditation (Text, 110)

55. The idea that God cannot be a deceiver leads to (See Text, 111)

56. God & the removal of doubt as to the existence of the external world (Text, 112-119)

57. The content of Meditation V l Mathematical thinking & its (physical & non-physical) objects: clarity & distinctness again -- what is clear & distinct must be true (112-113) l D’s “ontological” argument for the existence of God (115-116) l God & certainty (116-118)

58. Descartes’ third argument for the existence of God (the ontological argument again) (Text, 113-116)

59. 1. If the nonexistence of God (an infinitely perfect being) were possible, then existence would not be part of God’s essence (that is, existence would not be a property of the divine nature). 2. If existence were not part of God’s essence (that is, a property of the divine nature), then God would be a contingent (rather than necessary) being. 3. The idea of God as a contingent being (that is, the idea of an infinitely perfect being with contingent rather than necessary existence) is self-contradictory. 4. It is impossible to think of God as not existing. 5. The nonexistence of God is impossible.

60. Certainty about God is the basis of certainty about everything else. (See Text, 116-117)

61. Meditation VI Removal of doubt as to the existence of the external world l Since God exists l & is no deceiver, l it follows necessarily l that the external world can be known to exist. (See Text, 118-119)