Descartes: wax argument & knowledge

Descartes uses his wax argument, as described in my previous post, to construct a system of knowledge. He considers his perceptions to be unreliable, as he discovered in his wax argument, and he discards them completely when determining what he should base his knowledge on. He decides that only deduction can be used as a method for obtaining knowledge. At this point, Descartes brings God into his argument and decides that he must trust his senses at least a little bit. After all, God provided him with a working mind and sensory system. And, since God is benevolent, he does not desire to deceive Descartes in any way. Further, he believes that there is an external world because perceptions come to him involuntarily, and the things that he perceives must be external to his senses. From this, he finally entertains the idea that it may be possible that he may acquire knowledge about the world through both deduction and perception. Descartes further argues that knowledge is represented in the form of ideas and that rational knowledge is incapable of being destroyed.

Descartes: wax argument

Descartes uses what is known as his wax argument to demonstrate the limitations of the senses. He considers a piece of wax, and notes that his sense inform him of certain characteristics about that piece of wax. These characteristics include things like its size, shape, color, odor, texture, and so on. When he brings this piece of wax to a flame, however, these characteristics are completely altered. Despite these different characteristics, Descartes notes that it is still the same piece of wax as beforehand. Whether it is solid or liquid, hard or soft, hot or cold, it is still the same exact item. So, Descartes determines that he cannot rely upon his senses to determine the true nature of the wax, but rather upon his mind. He writes, "Thus what I thought I had seen with my eyes, I actually grasped solely with the faculty of judgment, which is in my mind." I like Descartes' wax argument because it shows exactly what he wanted to prove--the limitations of the senses. Your senses can obviously provide you with a ton of information, but they are incapable of reasoning through that information. That is what makes the mind so important--it must make sense of everything that the senses bring in.

Kant: metaphysics

Kant says that metaphysics relies on the faculty of reason, and therefore is independent of experience. Reason, he says, aspires to know about things in themselves and may sometimes mistakenly apply concepts of understanding to matters outside of experience. Kant says that there are three ideas of reasoning: psychological, cosmological, and theological. Psychological deals with our ideas and concepts of substance and the soul. Cosmological gives rise to four sets of antinomies, and theological obviously deals with our ideas of God. Kant argues that reason oversteps its bounds in each of these cases and often makes claims that can be confusing with appearances. Metaphysics, unlike mathematics and natural science, can go farther than it is reasonably capable of going, and in that way it can explore the full extent and capabilities of human knowledge. I'm a bit confused by the way that Kant talks about metaphysics, but from what I do get, it seems like he accepts metaphysics as something complicated and something he doesn't fully understand. I like that he doesnt try to make too many assumptions about it, and the arguments that he does present seem to make sense to me... but like I said, I don't entirely get it.

Kant: natural science

Kant thinks the same thing about natural sciences that he thought about mathematics. He believed that synthetic a priori judgments form the foundation of natural science. Pure natural science is possible, according to Kant, because of the pure concepts of our faculty of understanding. These concepts give a law-like structure to our experiences (one, for example, is that every effect has a cause). Kant is sure to distinguish between judgments of perception and judgments of experience. A judgment of perception is based on a subjective sensation, while a judgment of experience attempts to draw objective, necessary truths from experience. Since science is an objective body of knowledge, it must rely upon objective laws (pure concepts of our faculty of understanding). These laws are just as much apart of our understanding as are the concepts of space and time. So pure natural science is possible for the same reasons that pure mathematics is possible--they rely on parts of our natural concepts.

Kant: mathematics

According to Kant, the truths of arithmetic and geometry are synthetic judgments because they contribute significantly to our knowledge of the world. But these judgments are also a priori because they universally apply to all objects of our experience, without having been taken from the experience itself. The question then becomes, how do we come to have such knowledge? One might think that we indeed come to know these things through experience, rather than a priori. After all, you need to be familiar with numbers to even understand what 2 + 5 = 7 means. Kant argues that we know these things a priori because of "pure forms of sensible intuition," and not experience. He believes that things in arithmetic are directly associated with things in time, and things in geometry are directly associated with things in space. Space and time are absolute and derived from our minds. So, our concepts of space and time allow for us to understand mathematical concepts without being exposed to those concepts.

Kant- The first and second antinomies

The first two antinomies, the first having to do with space and time, and the second having to do with the simple and composite, both have opposing propositions (the thesis and antithesis). Whereas in the 3rd and 4th antinomies Kant argues that both the thesis and the antithesis are both actually true (and only mistaken to be contradictory when one takes phenomena to be noumena), Kant argues that the thesis and antithesis of the 1st and 2nd are both false. One might wonder how to contradicting propositions can both be untrue. It seems to be like the law of non contradiction in logic: P v ~P (P or not P), i.e., either something is the case or it is not. Kant explains that it is possible for two ocntradicting statements to both be false when "the concept lying at the ground of both of them is self-contradictory". Kant gives the example of a square circle. Two contradictory statements about square circles can both be false because the concept of a square circle is inherently contradictory. Because of that, any proposition which asserts anything about square circles is false. In the same way, when it comes to the question of whether or not space and time are infinite, or whether the constituents of the world are simply or composite, making any assertion of either the thesis or antithesis of either antinomy is assuming that experience is fit to give an answer. Becausethe world given to us IS equivalent to our experience, to suppose that our experience has the property of being simple or composite or infinite or finite is a mistaken notion.

Kant- The fourth antinomy

The fourth antinomy has to do with the existence of a first cause. Thesis: "In the series of world causes there is some necessary being". Antithesis: "There is nothing necessary in the world, but in this series all is contingent." Kant recognizes the objections raised by Hume in his Dialogues Concerning Natural Religion, where it is pointed out that we can not attribute qualities to the Supreme Being (such as understanding or will) because we can only do so by attributing anthropomorphic qualities to a being whom we cannot assume has them. Since we have our idea of will or of understanding only by reference to ourselves, we are not justified in assuming that God is like man. Kant says that we can refrain from doing this by using analogies. For example, although we cannot assume God to have rationality in the same way that we do, we can say that there is a rational structure to the world, and that

"reason is attributed to the supreme Being so far as it contains the ground of this rational form in the world, but according to analogy only, i.e., so far as this expression shows merely the relation which the Supreme Cause, unknown to us, has to the world in order to determine everything in it conformably to reason in the highest degree."

So although we may not be able to attribute properties directly to God (or a supreme being), we can attribute properties indirectly by way of analogy- by attributing properties to the relation which God bears to the world.