Descartes - Lecture 2
2. The Method of Doubt
THE INTELLECTUAL BACKGROUND CONTINUED
The Rediscovery of Ancient Scepticism
1562 – Henri Estienne publishes a Latin edition of Sextus Empiricus’ Outlines of Pyrrhonism
1569 – a Latin edition of all of Sextus’ works is published by the French Counter-Reformer, Gentian Hervet
1590/1 (according to Popkin) an English translation of the Outlines
1621 an edition of the Greek text.
Hervet’s reasons for publishing Sextus: Hervet claims that Sextus’ sceptical writings show that no human knowledge can resist the arguments that can be opposed to it. The only certainty we can have is God’s revelation. Scepticism by controverting all human theories and speculation will cure people from dogmatism, give them humility, and prepare them to accept the doctrine of Christ.
However in doing this good work, it challenges the authority of all varieties of metaphysics and physical science
DESCARTES’ RESPONSE IN THE MEDITATIONS
1) The development in a powerful form of sceptical arguments
2) The discovery of a truth that even these arguments cannot challenge
The cogito – I am thinking, therefore I am.
Other certainties associated with it – his essence as a mental thing, the content of individual thoughts
3) The truth rule and God (an initial argument)
God no deceiver and hence is a guarantor of the truth rule.
4) Descartes’ theory of error, an explanation of how we ever come to make mistakes
5) Uncovering the content of his idea of matter, a second argument for the existence of God
6) A real distinction between mind and body, body as conceived by him in the 5th Meditation exists, discussion of the interaction between mind and body
The Form of the Meditations
A set of intellectual exercises (fighting against tradition, human nature - our early dependence on the senses, and psychological inertia)
Descartes’ advice on how to read them, and his use of psychologically enlivening devices
Descartes’ experimentation with modes of presentation
The process of radically transforming the attitudes and beliefs of the reader
Ascensional and penitential meditational modes; analytic reconstruction – testing basic beliefs and dissolving them into their basic constitutive elements
Not genuinely autobiographical – unlike the earlier Discourse on the Method of rightly conducting one’s reason and seeking the truth in the sciences
The need to distinguish between the meditator and the author, even though Descartes uses ‘I’ to refer to the meditator
Common-sense views are ultimately radically revised
Responding to the Work
What are we to make of a work that begins with its narrator claiming that he needs to demolish everything completely and start again right from the foundations if he wishes to establish anything in the sciences that is stable and likely to last? After all, this doesn’t seem to be a procedure that is invoked by many of today’s scientists. Instead science seems to develop by making a succession of small changes that serve to increase the coherence and explanatory power of our belief set. Our existing beliefs are held open to revision, but most of them are retained even in the face of major scientific advances.
Furthermore the methods used to effect this demolition seem highly suspect.
Some it would be thought are plainly too weak – past errors, not entirely trusting that which has deceived us in the past; others are too absurd to be taken seriously.
Could it ever be sensible to criticise a scientist’s experimental results by suggesting that this scientist and his or her entire research team might have simply dreamt the experiment and its outcome?
Does long-term scientific success really depend on our having the ability to rebut the suggestion that an omnipotent divine being might be exercising his powers to deceive us.
What can possibly be gained from imaginatively projecting ourselves into a situation where we are minds are being manipulated by an evil demon?
What motivates such an apparently obsessive search for certainty?
THE FIRST MEDITATION AND THE METHOD OF DOUBT
Descartes’ summary in the Synopsis of what is achieved in the First Meditation
Reasons for doubt, especially about material things, ‘as long as we have no foundations for the sciences other than those which we have had up to now’.
Usefulness of such extensive doubt is not ‘apparent at first sight’
BUT its benefit is that it frees us from preconceived opinions and leads the mind away from its reliance on the senses
Ultimately this process of doubt makes it impossible to have any further doubts about the results that emerge from his subsequent investigations – taking the doubts of the sceptics further than they themselves have pressed those doubts – pre-empting the resources of the sceptical arsenal.
The Beginning
The false opinions acquired in childhood and the highly doubtful nature of the edifice he had subsequently based on them. Prompts the realization that he needs to demolish everything and start again from the foundations.
Descartes’ approach here can usefully be contrasted with the view that error is appropriately exposed gradually through a process of falsification arising from encounters with the real world. Bacon, the new science, and the importance of experiment. Chains v. ropes (no single fibre supports the weight dangling below). Neurath’s ship v. Descartes’ building. Descartes and his enthusiasm for the a priori reasonings of the geometers.
Descartes’ method of demolition – withholding assent from opinions that are not completely certain and indubitable.
Tipping out the basket of apples (seventh Replies 7.481)
All that is needed is to be able to find some reason for doubt.
Moreover needn’t run through all his beliefs individually – ‘once the foundations of a building are undermined, anything built on them collapses of its own accord’ - so he goes for ‘the basic principles on which all my former beliefs rested’.
A rival coherentist conception of justification – any particular belief is held in place/justified by its connections with a whole mass of sense experiences and other beliefs.
What are these basic principles on which the meditator’s beliefs are built? Descartes is primarily thinking of the trust we place in our senses.
Descartes’ initial objection to placing complete trust in the senses – past discoveries of sensory error – ‘prudent never to trust completely those who have deceived us even once’.
How carefully though do we have to specify ‘those who have deceived us’?
If one seeks directions to the University Botanic Gardens from members of the academic staff, then one will not always get the correct answer. But if one asks a member of the academic staff who has been employed here for several years, then one’s chances are distinctly better.
Descartes shows his appreciation of this point when he counters his initial ground for doubt by pointing out that sensory error in unfavourable conditions does not necessarily imply that sensory error is possible in favourable circumstances.
Deeper Grounds for Doubt
Seeking a ground for doubting the beliefs we ground on the senses when we think that the senses are operating in optimum conditions, Descartes initially points to the delusions of madmen. However he fails to endorse this ground for doubt – ‘such people are insane, and I would be thought equally mad if I took anything from them as a model for myself’.
On the other hand the meditator is made to acknowledge that when he is asleep and dreaming, he has experiences that are just as far removed from reality as the experiences of madmen. Moreover he has often been convinced that he was awake at times when he was, according to his present opinions on the matter, asleep and dreaming. Indeed on reflection he cannot think of any phenomenon that might occur in his waking life that would constitute a sure sign that he is not dreaming. Consequently he acknowledges that his present experience of sitting by the fire in his dressing ground might be part of a dream and hence might fail to correspond to how things really are.
At this point, we seem to be able to extract a general account of what suffices in Descartes mind for someone to have a reason for doubting the truth of the belief that p. We have a reason for doubting that p if we can construct an explanation of how we might come to believe that p even if it happened to be false that p.
The meditator’s response to the doubt based on the possibility that he is dreaming. Although dreams can be seriously deceptive, some of the basic features of such experiences are, he supposes, derived from encounters with reality – shape, extension, quantity, temporal duration, place, size, number.
Thus he concludes that those sciences that depend on the study of composite things are doubtful, while arithmetic, geometry and other subjects of this kind contain something certain and indubitable.
At this point, however, it is unclear whether Descartes wishes to maintain that they are certain because some things exist with the kind of properties they discuss or because they do not presuppose existence in nature. Are we still entitled to maintain that geometry contains some truths because there must be some extended objects to serve as its subject matter or because it does not actually make existential assumptions. Even if squares do not exist, it seems plausible to hold that it is necessarily true that if a square did exist, it would have four sides.
Irrespective of how we should interpret Descartes here, he then deploys another ground for doubt that is naturally read as targeting all the beliefs that he has just identified as surviving the dream doubt. This ground for doubt is discussed in Lecture 3
 Descartes - Lecture 3 |
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