Examining The Meditations (Part 9): Disparity Between Ideas And Objects

Entries in this series:

Examining The Meditations (Part 1): The Religion Of Descartes --https://thechristianrationalist.blogspot.com/2017/08/examining-meditations-part-1-religion.html

Examining The Meditations (Part 2): Cartesian Doubt --https://thechristianrationalist.blogspot.com/2017/08/examining-meditations-part-2-cartesian.html

Examining The Meditations (Part 3): The Ramifications Of Skepticism --https://thechristianrationalist.blogspot.com/2017/08/examining-meditations-part-3-descent.html

Examining The Meditations (Part 4): Illusion And Reality --https://thechristianrationalist.blogspot.com/2017/08/examining-meditations-part-4-illusion.html

Examining The Meditations (Part 5): "I am, I exist" --https://thechristianrationalist.blogspot.com/2017/08/examining-meditations-part-5-i-am-i.html

Examining The Meditations (Part 6): Mind-Body Dualism --https://thechristianrationalist.blogspot.com/2017/09/examining-meditations-part-6-mind-body.html

Examining The Meditations (Part 7): Classifying Thoughts --https://thechristianrationalist.blogspot.com/2017/09/examining-meditations-part-7.html

Examining The Meditations (Part 8): The Natural Light --https://thechristianrationalist.blogspot.com/2017/09/examining-meditations-part-8-natural.html


I left off in this series some time ago in part eight (sorry!), where I explained how Descartes discovers that it does not logically follow from him having an idea of a particular external object that such an object exists as anything more than a mental representation, because all that logically proves is that he has the idea of that object in his mind.  I will leap right back in, so read the previous post(s) if you need to see how Descartes got to this point in his book Meditations on First Philosophy.

He continues onward to explain how even if something does exist outside of him, his senses can distort certain information about it, like its appearance or size:


"And finally, even if these ideas did come from things other than myself, it would not follow that they must resemble those things.  Indeed, I think I have often discovered a great disparity <between an object and its idea> in many cases.  For example, there are two different ideas of the sun which I find within me.  One of them, which is acquired as it were from the senses and which is a prime example of an idea which I reckon to come from an external source, makes the sun appear very small.  The other idea is based on astronomical reasoning, that is, it is derived from certain notions which are innate in me (or else it is constructed by me in some other way), and this idea shows the sun to be several times larger than the earth." (27)


Descartes understands that even if external objects do exist, his senses might present them in such a way that they are actually quite different than they are perceived to be in some regards.  In this case he is not elaborating about the possibility that the sun does not exist even though he perceives it to.  In the last entry in this series I already went over how he recognizes that just perceiving an object doesn't mean it exists by logical necessity.  Here, instead, he means that even if the sun does exist, it doesn't follow from it seeming to be a certain way that it is as it seems to be.  In the example of the sun, he sees a small dot in the daylight sky that he calls the sun.  The sun is a star, a celestial body that provides light.  Scientific examination leads him to the conclusion that in actuality this sun he observes as small is multiple times larger than the earth he resides on.

Again, the point here is not that the sun does not exist (although Descartes has not proven that any external objects exist yet, and later fails to do so in a sound and valid manner), but that available sensory data can seem to contradict the notions that reason and empirical investigation point towards.  The sun cannot be both tiny by comparison to him and huge by comparison to the earth all at once.  I use reference points to judge size here because nothing is "big" or "small" in itself, just as nothing is "young" or "old" in itself; something is large or small only by comparison to something else.  Terms of size have no objective significance except in comparisons.  Descartes admits that only one of these two models in his mind can represent the actual sun:


"Obviously both these ideas cannot resemble the sun which exists outside me; and reason persuades me that the idea which seems to have emanated most directly from the sun itself has in fact no resemblance to it at all." (27)

The sun can appear to be very small by comparison to other things we see,
yet scientific investigation has yielded the idea that the sun is much larger
than the earth.  Descartes realizes that both cannot be true.  And if the
latter is true, then the "idea" of the sun provided directly by his senses
is somewhat misleading.

"All these considerations are enough to establish that it is not reliable judgment but merely some blind impulse that has made me believe up till now that there exist things distinct from myself which transmit to me ideas or images of themselves through the sense organs or in some other way." (27)


In part six of this series I showed how I know for sure that I have a physical body that my immaterial consciousness inhabits.  Just as in this series I have demonstrated how I know that my memory is reliable and that I have a body, I will now explain how I know that there is an external world, even if it doesn't resemble how it perceive it.  I will summarize how I know I have a body here because it is very relevant, but go read part six again if you need to see a deeper explanation.  In short, I cannot experience any physical sensations (touch, temperature, pain, and so on) unless I have some sort of physical body with which I can experience them, as a mind is immaterial and by itself could not experience such things.  Only a physical body could receive physical sensations.

With the fact that I have a body established, it next becomes logically evident that my body houses the senses which make me aware of its existence.  My senses also report physical sensations that originate outside of my body.  I do not know if I am perceiving the world outside of my body as it truly is, but I know with absolute certainty that I am contacting something external to me (in this case by "external to me" I mean outside of both my mind and my body).  This much I can know through logic and experience.  I may expand this abridged explanation later in this series, but for now, it will suffice.

At this point, Descartes thinks of another possible pathway to verifying the existence of external objects:


"But it now occurs to me that there is another way of investigating whether some of the things of which I possess ideas exist outside of me." (27)


Descartes moves to an analysis of causality in the next pages.  Approaching his argument for God's existence, he hopes to verify the reliability of his senses by showing that God is not a deceiver.  I hope to continue this series again before the year's end!