The first was what remained of the mediaevalscholastic philosophy, largelybased on Aristotelian science and Christian theology. Descartes had beentaught according to thisoutlook during his time at the Jesuit college La Flech and it had animportant influence on his work,as we shall see later. The second was the scepticism that had made asudden impact on the intellectualworld, mainly as a reaction to the scholastic outlook. This scepticismwas strongly influenced by thework of the Pyrrhonians as handed down from antiquity by SextusEmpiricus, which claimed that, asthere is never a reason to believe p that is better than a reason not tobelieve p, we should forget abouttrying to discover the nature of reality and live by appearance alone.
This attitude was bestexemplified in the work of Michel de Montaigne, who mockingly dismissedthe attempts oftheologians and scientists to understand the nature of God and theuniverse respectively. Descartes feltthe force of sceptical arguments and, while not being scepticallydisposed himself, came to believethat scepticism towards knowledge was the best way to discover what iscertain: by applying scepticaldoubt to all our beliefs, we can discover which of them are indubitable,and thus form an adequatefoundation for knowledge. The third world-view resulted largely from thework of the new scientists;Galileo, Copernicus, Bacon et al. Science had finally begun to assertitself and shake off its datedAristotelian prejudices.
Coherent theories about the world and its placein the universe were beingconstructed and many of those who were aware of this work became veryoptimistic about theinfluence it could have. Descartes was a child of the scientificrevolution, but felt that until scepticalconcerns were dealt with, science would always have to contend withMontaigne and his cronies,standing on the sidelines and laughing at science’s pretenses toknowledge. Descartes’ project, then,was to use the tools of the sceptic to disprove the sceptical thesis bydiscovering certain knowledgethat could subsequently be used as the foundation of a new science, inwhich knowledge about theexternal world was as certain as knowledge about mathematics. It wasalso to hammer the last nailinto the coffin of scholasticism, but also, arguably, to show that Godstill had a vital rle to play in thediscovery of knowledge.
Meditation One describes Descartes’ method of doubt. By its conclusion,Descartes has seeminglysubjected all of his beliefs to the strongest and most hyberbolic ofdoubts. He invokes the nightmarishnotion of an all-powerful, malign demon who could be deceiving him inthe realm of sensoryexperience, in his very understanding of matter and even in the simplestcases of mathematical orlogical truths. The doubts may be obscure, but this is the strength ofthe method – the weakness ofcriteria for what makes a doubt reasonable means that almost anythingcan count as a doubt, andtherefore whatever withstands doubt must be something epistemologicallyformidable.
In Meditation Two, Descartes hits upon the indubitable principle he hasbeen seeking. He exists, atleast when he thinks he exists. The cogito (Descartes’ proof of his ownexistence) has been the sourceof a great deal of discussion ever since Descartes first formulated itin the 1637 Discourse on Method,and, I believe, a great deal of misinterpretation (quite possibly as aresult of Descartes’ repeatedcontradictions of his own position in subsequent writings). Manycommentators have fallen prey tothe tempting interpretation of the cogito as either syllogism orenthymeme.
This view holds thatDescartes asserts that he is thinking, that he believes it axiomaticthat ‘whatever thinks must exist’ andtherefore that he logically concludes that he exists. This view, itseems to me, is wrong. It should bestated on no occasion, in the Meditations, does Descartes write ‘I amthinking, therefore I am’, noranything directly equivalent. Rather, he says:”Doubtless, then, that I exist…and, let him deceive me as he may, he cannever bring it about that Iam nothing, so long