Descartes did not believe that the information we receive through our senses represents the external world accurately. True knowledge only comes from pure reasons.
I can agree with you to a point that Descartes did not believe that the information we receive through our senses (a-posteriori knowledge) represents the external world accurately. This is one of the fundamental quantifiers that make Descartes a rationalist to begin with, instead forcing him to lean towards innate ideas (a-priori knowledge) as the source of human knowledge. But there are more caveats to Descartes rationalism. You also hint at what I am getting at because you refer not to senses that represent the world alone but represent them accurately
. This is a fundamental premise in Descartes Meditations
, which is that there must be a degree of what we can know through rationalism to be clearly and distinctly
known. This is a primary issue that Descartes examined in his previous book Discourse on Method
in which he must deliver upon in Meditations
. Descartes must as Discourse
implies, doubt everything (except what can be known clearly and distinctly), analyze down to the simplest component, reconstruct them so that the method is as clearly and distinctly know as before you had deconstructed them, and enumerate over and over again.
Do you agree with Descartes that sense can be deceived.
As far as Descartes is concerned, sure. The first meditation gives a pretty wiz-bang account of universal doubt. As far as the first meditation is concerned for example, most things cannot be trusted to be known clearly and distinctly by whatever it is that accounts for these thoughts (because he has yet to rationalize himself into existence). Look at the dream argument in med. Med. On First. Phil, Meditation
Can you help me find some examples?
The best place to look is probably within the framework of Meditations
. In Meditation 2
, Descartes gives what I would consider a perfect example of what you may be getting at, namely the ball of wax argument. To begin with, Meditation 2
is essentially basing itself off of two derived points, that; Descartes has mental states therefore he exists, and that it is an a-priori (before the senses) form of knowledge. As a side note, this is the true interpretation of the conclusion of the universal doubt argument. "I think, therefore I am" (cogito ergo sum) comes later in another one of Descartes books. Descartes specifically says Res Cogitans
(I am a thinking thing) which implies the mental faculties involved rather than the whole of his argument encapsulated in one neat and tidy saying given later on for ease of use. But anyway, the ball of wax argument is essentially resuming his method, namely that after everything is doubted, he must now construct what he knows clearly and distinctly. It is essentially drawing a distinct line between the fundamentals of empiricism (yet to be conceived in its modern form by Locke) and rationalism (which Descartes does not attribute to himself at this point). It is in this example that Descartes proves that what is known is known by reason and not by sense.
The ball of wax argument goes something like this. Suppose I have a ball of wax fresh from the beehive. It has a certain amount of qualities, such as the fact that it is round, yellow, etc. Take all of these properties and label them Wax #1 with qualities 1-10
. Now suppose I put Wax 1 with qualities 1-10
next to the fire. Inevitably, the ball of wax loses its size, shape, color, etc. It in essence becomes a different ball of wax, namely Wax 2 with qualities 1-10
. This seems like a no brainer, but this was huge when Descartes posited this. We know that Wax 2
is the same ball of wax as Wax 1
. But how do you rationalize it. It's not as simple as saying "I saw the ball of wax as it melted" because there is there very real possibility that you blinked, turned around, etc. Descartes specifically points out that you cannot know the wax in either of its forms by its properties (color, shape, etc) because the properties have changed. So a "thinking thing" has to deduce via some form of a-priori capacity that that there is an understanding beyond properties that "thing" already understands.
rcs;79256 wrote:An Essay Concerning Human Understanding
To what extent will you trust the deductions made on the grounds of sense and perception?