Descartes' Method

The first [rule] was never to accept anything as true that I did not plainly know to be such. (18)

I formulated a provisional code of morals . . . to obey the laws and customs of my country, constantly holding on to the religion which, by God's grace, I had been instructed from my childhood, and governing myself in everything else according to the most moderate opinions and htose furthest from excess. (22-23)

As I think several of my fellow posters have pointed out, Descartes claim of taking nothing for granted is perhaps not very strong. While he doubts a considerable amount, he leaves out at least one essential: his ability to reason logically and accurately. If indeed there were an "evil deceiver," wouldn't this deceiver be capable of twisting Descartes' mind so that what he believes to be logical is in fact a fallacy? "Je pense donc je suis" appears to be logical, both to Descartes and to us. But how do we know our perception of "logical" is not skewed? We can't know this, and neither can Descartes.

Therefore, Descartes does not doubt everything; he keeps faith in his reason. This would certainly appear to negate all his further claims (if his original premise - je pense donc je suis - is incorrect, all further conclusions must also be incorrect). However, I wonder if his method is nevertheless effective. I think that Descartes realizes that if he doubts his reason, he will never be able to know anything, and by studying the way in which he devises a "provisional code of morals" we can see more clearly his response to this difficulty. He decides that it is better to have faith in something than to doubt everything and accomplish nothing (this goes back to Dante, or Eliot, who argued that "the way up is the way down" and any movement is better than none). This may lead him to error, but at least he has a chance of discovering the truth. So, once again, he has placed that faith in his reason. How else could he choose the criteria for his morals? By what standards does he judge this provisional code?

Descartes’ method cannot give him complete or perfect knowledge, but it does provide a better basis for his beliefs. It helps him to apprehend more fully God, himself, and the created world, and this apprehension helps him live and strive productively. Although he does not state it as such, as long as he does not doubt his mind, this then must be his goal. Whether the world he senses is real is finally unimportant; Descartes cares not whether it is real, but how best to deal with it.