laura@utcsstat.UUCP (Laura Creighton) (01/12/84)
This started out as an introduction to Dave Hume's Empiricism. It grew too big for this. (There's an essay in here somewhere -- now I just have to find the appropriate course to modify this and submit it to...) Okay. Back to Descartes. What did we leave with? Descartes' ideas of the self, truth as mathematical knowledge, and God. I have mentioned that the proof for the existence of God is not watertight. The other thing which needs mentioning is that while Descartes' proof of the existence of God may be not be watertight, even if it *were* watertight, the God whose existence was proved is not necessarily the Christian God. Yet Descartes seems to take this for granted. If you find that this is very strange, remember that Descartes was a Christian (and as such knew what the answer was before he started) and, more importantly, that the 16th century was a time when heretics got sent to the inquisition.. Now what Descartes has set out to do is lay a foundation for the study of knowledge. Before examining his foundation, and looking for cracks, it is necessary to determine whether the whole idea of a "foundation for knowledge" is itself a good one. Simple examination is enough to let one know that a search for 'a natural number that is both odd and even' is doomed and that one should not waste time at it since natural numbers are, by definition, either even xor odd. it may be that Descartes' whole idea is a search for a similar thing, in which case epistemology is a rather useless (if interesting) exercise and should be abandoned. So what is knowledge? More to the point, is it univocal? If it has one meaning then we should determine what it is and study it. If it is equivocal then we are not out of business yet, since it is possible that while what is commonly meant by "knowledge" has many meanings, they all share a common property. For example, "dogs" and "cats" are different ideas, and mean different things, but there are several things which they have in common. By studying these common things one can arrive at an understanding of the two distinct ideas. On the other hand, we may simply have had it, and it will be time to conclude that we should pack the study in. No doubt if you worked at it you could produce a property that is shared by Adolf Hilter and daffodils (for instance, that neither of them has a "z" in their name) but this is so useless as to add virtually nothing to our understanding of either Hitler or daffodils. So, let us see if the word "know" is univocal. What do I know? Let us take some random examples: 1 I know that 2 + 2 = 4. 2 I know that I love strawberries. 3 I know that Paris is the capital of France. 4 I know that the sum of the angles in any triangle is 180 degrees. 5 I know how to swim. 6 I know Toronto. 7 I know that UNIX is a good thing. 8 I know that there are still bugs in our curses library. 9 I know my friend. 10 I know that my friend hates vegetables. Okay. The list could go on forever, but this will serve. Now, clearly I say that I "know" all of these things, but also clearly I do not mean the same thing by the word that I use. Numbers 1, 3 and 4 have to do with things that I know are true *by definition*, number 2 has to do with my own mental state, number 5 is an ability that I have, numbers 6, 8, and 9 deal with things that I have a direct acquaintance with. Number 7 and number 10 are hard. A lot of people hate UNIX. I think that they are wrong, but I have had serious arguments on the subject, so the issue is not as obviously true as number 1. Number 10 is real hard. My friend may be lying when he tells me that he hates vegetables. he may have never tried any for 10 years and thus not be in a position to know if *right now* he still hates vegetables. Perhaps he only hates certain vegetables. Getting inside somebody else's head is not possible, so while I can look for supporting or conflicting evidence there is little that I can do except believe or disbelieve his claim to hate vegetables. Okay. "To know" is equivocal. However, it is possible to reduce all of the above sorts of knowledge into 2 categories -- a priori knowledge, or knowledge by definition (mathematical knowledge), and knowledge by experience (empirical knowledge). I have not experienced that 2 + 2 = 4, and I do not like strawberries by definition. (It is possible to have a composite. Thus I know that Toronto is the capital of Ontario by defintion, but I also am well acquainted with Toronto since I live here.) is this conclusion reasonable? Does all knowledge depend on experience or a priori truths? This, of course, is the 64,000 dollar question, but I can present some supporting evidence. In English there is only one word "to know" which gets used for both of these senses of know. However, other languages make the distinction. In German, the difference is between "wissen" and "kennen", in Spanish between "saber" and "conocer", in French between "savoir" and "connaitre". There are similar distinctions in Portuguese and Italian. This is hardly conclusive proof that there are actually only 2 senses of the word "know", but it is encouraging. The next question is does the empirical know (kennen) have anything to do with the a priori know (wissen)? Clearly the English, who optimised themselves out of a word thought so, but even in the other languages I have mentioned there are cases where you can use *either* of the verbs "to know". For the time being we will decide that the senses of know have more in common than Hitler and daffodils and thus it is profitable to look for the common principle. HERE I AM GOING TO INTRODUCE A SIMPLIFICATION. Rather than look for what the 2 "knows" have in common, I will state that either one is derived from the other, or vice versa. This is a simplification, but I do not feel a serious one (at least now). Descartes and Hume both made this simplification themselves. The difference is that Descartes thought that all knowledge came from a priori knowledge and principles which were true by definition, while Hume thought that our a priori knowledge was derived from our empirical knowledge. Both views have merit, but they produce radically different world views. Laura Creighton utzoo!utcsstat!laura