1 The Rationalists: Descartes The Material World Soazig Le Bihan - University of Montana Jack Nichols, Living in the material world

2Introduction What we have recovered: rational truths within the mind Soazig Le Bihan - University of Montana What remains to do: existence of the external bodies The central pillar of the argumentation: God is not a deceiver

3Outline Soazig Le Bihan - University of Montana 1.Introduction: What obstacles do we have to pass to recover the material world? 1.The existence of the corporeal substance as separated from the substance of thought 1.The truth within the teaching of nature

4Introduction The obstacles Soazig Le Bihan - University of Montana All we have for now: the truth of our clear and distinct ideas Why did we reject the existence of the material world? -Senses and feelings can be deceitful -Even if I feel like they originate in something external, it may be the case that they result from unconscious processes within me -Dream argument and Evil Genius

5Outline Soazig Le Bihan - University of Montana 1.Introduction: What obstacles do we have to pass to recover the material world? 1.The existence of the corporeal substance as separated from the substance of thought 1.The truth within the teaching of nature

6 The existence of the Corporeal Substance Overview Soazig Le Bihan - University of Montana Structure of the argument: 1Imagination: the good probability that my body exists 2The essence of the corporeal essence is radically different from the essence of thought 3The corporeal substance exists.

7 The existence of the Corporeal Substance Step 1 : Imagination Soazig Le Bihan - University of Montana 1Same starting point as in Med. 5: images of bodies – clear and distinct idea of the corporeal essence (extension in time) 2The fact that I can imagine suggests that I am not only a thinking thing, but that I also have a body: -Imagination is different from pure intellection -Inference to the best explanation: body

8 The existence of the Corporeal Substance Step 2: distinction body / mind Soazig Le Bihan - University of Montana 1Premises: a.I have a C&D idea of the essence of thought b.I have a C&D idea of the essence of bodies 2Nerve of the argument: It is sufficient to be able to clearly and distinctively conceive one thing apart from another to conclude that they are essentially different 3Conclusion: - the essence of bodies is radically different from the essence of thought - if bodies (including mine) exist, then they exist as separated from the substance of thought

9 The existence of the Corporeal Substance Step 3 : The corporeal substance Soazig Le Bihan - University of Montana Argument’s structure: 1Imagination, Sensations and Feelings indicate the existence of some external substance – passive 2Such external substance must be the corporeal substance Nerve of the argument: God is not a deceiver ! - I naturally believe that imagination, sensations and feelings originate in external bodies - There is nothing hidden in me - SO: I can trust my natural belief

10 The existence of the Corporeal Substance Conclusion Soazig Le Bihan - University of Montana Descartes’ main point: - Because the corporeal essence is radically different from the substance of thought - And because God is no deceiver - We are now justified accept the argument that our passive feelings and sensations come from something different from us and that this thing is the corporeal substance

11Outline Soazig Le Bihan - University of Montana 1.Introduction: What obstacles do we have to pass to recover the material world? 1.The existence of the corporeal substance as separated from the substance of thought 1.The truth within the teaching of nature

12 The Teachings of Nature The Truth within Sensations and Feelings Soazig Le Bihan - University of Montana Same argument again: Because God is no deceiver, there is some truth in my sensations and feelings about external bodies First truth: my whole self consists in an union of the body and the mind Second truth: sensations and feelings teach me what is harmful/ useful within the effect external bodies on myself

13 The Teachings of Nature When are the senses deceitful? Soazig Le Bihan - University of Montana Sure fire mistake: Whenever I interpret my sensations as corresponding to properties of external bodies: Examples: color, heat etc.  Not God’s fault, but mine for misinterpreting the significance of the teachings of nature! Genuine possibility of deceit? Example: the case of dropsy  Descartes’ answer: strings of causes

14 Conclusion on the Material World Soazig Le Bihan - University of Montana What we have recovered:  The existence of a corporeal substance, separated from the substance of thought  The existence of the union between body and mind which constitutes my whole self  The (most often) truthfulness of the teachings of nature concerning how external bodies relate to mine What remains unknown  The properties of external bodies  No perfect method for discerning the truth within sensations and feelings

15 Conclusion on the Material World Soazig Le Bihan - University of Montana

Conclusion on Descartes EPISTEMOLOGYMETAPHYSICS Method of doubtI exist Clear and Distinct IdeasRational Truths exist in my mind Rational knowledge superior to knowledge from the senses Truthful God Theory of errorTheory of free will / autonomy FoundationalismConstituents of reality: 1.Thought 2.Corporeal substance 3.Union Soazig Le Bihan - University of Montana16