In his sixth meditation Descartes must return to the doubts he raised in his first one. Here he deals mainly with the mind-body problem and tries to prove whether material things exist with certainty. In this meditation he develops his dualist argument; by making a distinction between mind and body; although he also reveals that the are significantly related. He considers existence of the external world and whether its perception holds any knowledge of this world. He also questions whether this knowledge is real or is merely an illusion. He makes it quite clear how misleading and deceiving some external sensations can be.
In the beginning of this last meditation he attempts to prove the existence of external object. One way of achieving this is by recognizing the distinct ideas he had of external objects are thoroughly imprinted in his memory, he realizes that the concept of these ideas could not have originated from his mind. Therefore holding the clear knowledge of these objects was a projection of other objects. He realized he had no description of these objects except what they themselves reflected subsequently these objects resembled the ideas which they caused. According to Descartes the only direct experience one can have is the nature of our own ideas and we do not realize how our own appreciation of certain concepts may be very different from the objective character of the external world.
Descartes believed mind and body to be separate entities, however he also believed them to be closely interconnected. He reduces the body to be an extension of the mind but without thought or intellect. He pursues this argument by stating that he (his mind) does not need his body to exist. He also says that the body cannot without intelligent substance attached to it. He adds to this that nothing can assist better to preserving the body than what the mind itself feels but also reminds us that this mind and body experience can be deceiving, as sometimes what one feels is right for oneself is actually not. “Thus for example, the pleasant taste of some food in which poison has been mingled may invite me to take this poison and thus to be deceived.” Here he states how easily we can be deceived by our senses.
He accepts that matter exists as long as it is not a projection of his own mind or God. As Descartes previously established the existence of God as a perfect being, he therefore has concluded that God is not a “deceiver”. This very clear concept leads him to accept his clear and distinct sensory experiences are a result of external objects of material nature. Once these tangible objects can be considered as self-evident ideas, they can no longer be products of the mind.
Another way in which Descartes proves the existence of material substances is by showing that pure intellect is controlled by will, therefore anything can be easily ignored. While imagination is not controlled by will, consequently it is impossible to restrict imagination, matter must exist, as without the subsistence of things to imagine there would be no imagination.
Descartes sixth meditation is conclusive and holds very basic concepts. He exposes his dualist ideas but he does not exaggerate or make them absurd as he also continually reminds us of the great importance of the mind and body relationship. Descartes regards the mind to being of critical importance concerning perception and sensation. He arrives at the conclusion that external objects do in fact exist by stating a series of ideas that seem to give a clear answer. He ends up believing that external objects cannot be merely product of the imagination since what be imagined if there was nothing there. He also refuses to believe God will deceive us in such way, therefore what we see before our eyes is actually there.