Examining The Meditations (Part 8): The Natural Light

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): Descent Into 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


I left off last time where Descartes realizes that all ideas of his have one of three points of origin: 1) innate, 2) acquired, 3) created by him.  Having proven that sensory perceptions demonstrate to him that the perceptions exist as ideas in his mind, he sets about trying to discover if his ideas of external objects prove that material objects truly do exist objectively outside of his own mind.

He wonders where certain ideas about the external world come from:


"But the chief question at this point concerns the ideas which I take to be derived from things existing outside me: what is my reason for thinking that they resemble these things?  Nature has apparently taught me to think this.  But in addition I know by experience that these ideas do not depend on my will, and hence they do not depend simply on me.  Frequently I notice them even when I do not want to: now, for example, I feel the heat whether I want to or not, and this is why I think that this sensation or idea of heat comes to me from something other than myself, namely the heat of the fire by which I am sitting." (26)


I may walk around outside on a cold day and wish in my mind for the cold to vanish, yet my inner will does not affect my sense of thermoception (sense of temperature); I still feel the cold of the air regardless.  One's inability to control external sensations may seem like very strong evidence that the sensations are caused by objective external phenomena and not one's own mind.  Still, as Descartes will soon acknowledge, this alone does not prove their origin in the external world; it currently only proves that the ideas of external objects exist in his mind and that he cannot will his sensory perceptions away with his mind.  In part six of this series I did explain how a person can know if he or she has a body, though, and one does not need to demonstrate that God exists to know this, as Descartes seems to currently believe.  It is much easier to logically verify if any external world exists at all from that point [1], an explanation that I have given elsewhere and will save for a later point in this series.  But Descartes sees that reason does not yet verify an external world:


"When I say 'Nature taught me to think this', all I mean is that a spontaneous impulse leads me to believe it, not that its truth has been revealed to me by some natural light.  There is a big difference here.  Whatever is revealed to me by the natural light - for example that from the fact I am doubting it follows that I exist, and so on - cannot be in any way open to doubt." (27)


The natural light spoken of here seems to be the illumination of reason, a thing which, when used without fallacies, is infallibly reliable, for reason itself is infallible and one's human ability to reason is infallible to the extent that it is aligned with reason itself.  Descartes says here that it still is not apparent by use of reason that the source of his ideas of external objects is an external world that he can know exists by logical necessity (it is an untested spontaneous impulse), for although he has certain ideas of external objects it does not follow from his mental awareness of these ideas that they were impressed on him from an outside source.  To use that as an argument would have belief in the external world hang on an unverifiable non sequitur.  This spontaneous impulse that compels him without as-of-yet proven reason to believe his ideas of external objects must originate from the external world does not have the natural light on its side, and thus it cannot yet be known to be true, for only what the natural light demonstrates is true by necessity.  It is not that no one can doubt what reason, the natural light, reveals, but that whatever the natural light (logic) truly reveals must be true and cannot be false.

Descartes then offers a possible explanation for the origin of his ideas of external objects:


"Then again, although these ideas do not depend on my will, it does not follow that they must come from things located outside me.  Just as the impulses which I was speaking of a moment ago seem opposed to my will even though they are within me, so there may be some other faculty not yet fully known to me, which produces these ideas without any assistance from external things; this is, after all, just how I have always thought ideas are produced in me when I am dreaming." (27)


Here Descartes hypothesizes that perhaps he has an unknown subconscious part of his mind which generates ideas of external sensations, with his conscious mind directly perceiving them, free to will them to disappear in vain.  When dreaming, unless one is lucid dreaming, one's mind perceives images without having any conscious control over what images appear and without the senses being active.  This analogy is a very valid comparative illustration of what Descartes means here.  Without yet having identified a logical proof that some sort of material external world exists, he continues investigating his ideas and holding up the possibilities against reason, the infallible natural light.


[1].  https://thechristianrationalist.blogspot.com/2017/08/the-external-world.html