1. Descartes’ goal in the Meditations is to discover and establish an absolute certain truth that cannot be doubted. By achieving this goal, Descartes would therefore find a clear and indisputable foundation for all human knowledge. However, the problem with this approach is a type of skepticism and a form of doubt. Namely, it appears that all possible candidates for absolute truth could be doubted. Hence, even very basic claims about everyday existence, as Descartes argues, could be challenged as to their truth. Taking this challenge of radical skepticism, therefore, Descartes uses it can be said the enemy as his friend: he puts all possible considerations for absolute truth in doubt to find something that cannot be doubted.
Descartes uses this method because of its power to discredit many candidates for absolute truth. From this same perspective, thus, Descartes therefore according to his methodology of doubt cannot use what he has already been taught since he understands that much of what he has been taught is precisely subject to doubt. At the beginning of the Meditations, therefore, Descartes alludes to the fact that much of what he had been told as a youth turned out to be false. Descartes’ starting point is thus that all existing forms of knowledge must be put under the scrutiny of a radical form of doubt, so as to discover if there does in fact exist a proposition or a statement that could escape such skepticism.
2. The purpose of the dream hypothesis in Descartes’ first meditation is to show how even propositions which we think are common sense and true can also be doubted. For example, if I say it is certainly true that I am behind my computer typing this essay for my philosophy exam, it could be argued that I am dreaming that I am doing this work. Therefore, Descartes is trying to demonstrate how even common sense propositions could be doubted, the propositions which we take for granted in our everyday lives. The evil genius hypothesis has a similar point, but is perhaps a more radical version of this same concept. Someone could state that I am sitting on a chair in the kitchen, but it could be argued that perhaps all that the reality we see around us is the creation of a powerful being, an illusion meant to decisive us. Descartes ultimately eliminates the evil genius hypothesis based on his absolute truth “I think, therefore I am”: even if the genius tricks me about what I am thinking about, I am still thinking. This argument of the evil genius will thus play a key role in Descartes’ later conclusions, since he essentially separates what we think about from the act of thinking itself and therefore believes to have achieved the foundation for truth and knowledge that he desires to uncover.
3. Descartes uses the wax example to show that physical knowledge of material bodies are insufficient for absolute truth. For example, we take a piece of wax and melt it: what can we say are the essential properties of the wax? Descartes argues that nothing, because the wax completely changes and is ultimately destroyed in the fire. He succeeds in showing how bodies and material are ultimately unstable phenomenon. This is a key argument, because it supports his rationalism, namely, that we have to look for absolute truth in our own minds. In other words, if the physical world around us is essentially one that is subject to degeneration, with substances disappearing before our eyes, or changing into unrecognizable forms, it would be an error to base our knowledge on these phenomena, since by doing so, we are assuming that they are stable. Thus, Descartes’ rationalism, which is closely tied to the primacy of the mind and thought in his Meditations, is also established by the skepticism applied to the physical world around us.
4. Descartes arrives at his famous conclusion, “I think, therefore I am”, as the answer to his search for a proposition that cannot be doubted and therefore serve as the building block and foundation for human knowledge. This conclusion is thus the product of his application of doubt and skepticism: in so far as the content of what we think about may be doubted in terms of its validity, there is still a thought itself which exists. But this conclusion still leaves open many unresolved issues. For example, even if we can say that we think, and therefore in one sense that we exist, what does this existence mean? In other words what does the “I am” mean in this proposition? For example, if we tie the “I am” to “I think” does that mean that I only exist as a disembodied mental idea, with no physical body? What happens, in contrast, if the thought that I think I am thinking is not a sufficient foundation for my existence as an individual person? It appears that the key problem at this point for Descartes is, even if we accept that there is a mind that thinks, how does this become a foundation for explaining the existence of the physical and material universe around us. By relying solely upon the mind as a foundation for his meditations, Descartes then still has to provide an adequate account of the physical bodies that exist around us. He has to make a type of “quantum leap” from mind to body, but in one sense, Descartes rejects this possibility, since he maintains a type of mind-body dualism, which suggests that in one sense this problem cannot be resolved.
5. Lao Tzu would most likely respond critically to Descartes’ main conclusions. This is because Lao Tzu would stress that Descartes is overemphasizing the mind in his account and disregarding the appearance of the human being in a cosmos, as part of some type of cosmological order. For Lau Tzu, it appears that there is not the same suspicion of the physical world and its unreliability for knowledge as there is for Descartes. From Lao Tzu’s point of view, Descartes perhaps argues for a simplistic dualism between body and mind that clearly overlooks the importance that our bodies and our part of the physical world has with regards to the very key to our existence. In other words, to exist is basically to exist as part of some type of cosmic order and this is the very crux of the problem, but Descartes instead rejects this cosmic order, our connection to nature and the world around us, because he feels that it is too unreliable. Lao Tzu, in this sense, would reverse Descartes’ thesis: if the mind can lead us to play skeptical games about the world around us, it is not our individual minds that is the location of truth, but rather we should look beyond the mind since it is the source of our problems in the first place. Descartes would most likely respond by using one of his arguments such as the evil genius or the dream hypothesis: how can we be certain that we do exist in such a world, beyond our senses of this world? For Descartes, this foundation is simply too shaky to be considered a starting point for serious knowledge. Therefore, for Descartes, Lao Tzu’s proclamations do not satisfy the standard of a radical doubt which drives the Cartesian method and in Lao Tzu’s theory there are simply too many ungrounded assumptions to serve as an adequate foundation for human knowledge.