June 1: Theory of Knowledge
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To do for next class - 1) Read pp.304-349; 2) What do you think of the skeptics position? 3) What is epistemology and how is it important? |
To do for next class - 1) Read pp. 350-562 and pp. 377-386 2) What other parts of philosophy does the relation between theory and observation relate to? Why? 3) What shortcomings are there of the scientific method? |
Introduction
Epistemology was one of the first concepts we met in our introduction to philosophy. Do you remember what the context was? (A means of unifying human nature and the universe). What is epistemology? (Theory of knowledge; literally the study of knowledge). What kinds of questions do epistemologists ask? (What do I know? How can I know anything? What can I be certain of knowing? What are the limits of my knowledge? What is it to know something? Where can knowledge come from?) Can you name a few different kinds of knowledge? (A priori, a posteriori, propositional, non-propositional, procedural knowledge) What are some examples?
The philosophers who have been interested in discussing these sorts of questions about what we can know are called epistemologists. Epistemology was practiced since Plato's, Socrates' and Aristotle's day, but only gained that title in the 17th and 18th centuries. Despite the antiquity of its problems, it is still on of the most hotly debated areas of philosophy.
Descartes' meditations
Descartes is perhaps the most often quoted philosopher. We have all heard the pithy "I think, therefore I am". Of course, Descartes never actually wrote that in the Meditations, where he argues most strenuously for it. Nevertheless, it is an accurate portrayal of a central conclusion of his - a conclusion which supports his belief that we can have certain knowledge. Descartes is also famous outside of philosophy for his 'Cartesian' coordinate system which is the standard in much of mathematics. In fact one of his great ambitions was to provide a mathematical foundation for all of science. He was also a teacher of Queen Christina of Sweden (who woke him up to early and caused his death). But for our purposes, it is Descartes method of doubt and his conclusion (the cogito) which are of interest.
Descartes' method
Descartes asks a question: What can I surely know? What can I be certain of if I doubt absolutely everything? Does this question strike you as strange? How would you respond if some one told you everything you experience is just a dream? These questions probably seem less 'far out' nowadays than they did in Descartes day. We know precisely how amazing the human mind can be, how real hallucinations seem and how disorienting virtual reality is (30 mins to change physics models). Nevertheless the questions are odd. Who really doubts that we are different people standing on the planet earth? Well, Descartes tried to. He thought that if he could doubt everything that was at all doubtable whatever was left would be certain knowledge. Once you have certain knowledge, you have unimaginable power to build up a convincing philosophical and scientific system. That was Descartes' ultimate goal.
His method is not simply one of doubt. It is also one of inquiry. He is trying to find something out - what is certain knowledge. He is assuming that there is something we want to know that no one else already knows. Furthermore, his "method of doubt" is not simple doubt, it is absolute doubt. We can not just think "maybe what I'm seeing is an illusion", we have to assert "everything I ever see is illusory" -- and see what we are left with. Anything we can possibly doubt must be doubted. Can you think of something it is impossible to doubt? Perhaps the best way to conceive of absolute doubt is to assume there is an evil demon (a Cartesian demon) whose sole purpose it is to trick you (a grand conspiracy). The evil demon is extremely powerful and so can alter all of your perceptions to make anything look like any other thing. This sounds weird? Well, Descartes imagined this exact situation.
What did Descartes do with this situation? He doubts everything. Absolutely everything? What did he find it impossible to doubt? His own existence. Cogito ergo sum (the cogito). Translated: "I am thinking, therefore I exist". Did Descartes do a good job of doubting? Is it possible to doubt even more? What were the results of Descartes position? (Solipsism; Subject of knowledge is more important than the object).
What is the epistemological turn? (The change in focus from ontology to epistemology instituted by Descartes.) Why is it important? It is important because for 2000 years before Descartes, questions of what exists were seen to be fundamental to all other questions (metaphysics took precedence over epistemology). (Wolff introduces the 'car' analogy with a logical engine). Using Descartes' method, questions of being must be set aside until questions of knowing have a satisfactory resolution. We must not, according to the method, stipulate anything. Nevertheless we must achieve absolute certainty. For many, strict adherence to this method results in absolute skepticism - the belief that we can't know anything. However the purpose of this method (and the resulting skepticism) is not to get us to stop believing (like the skeptics - wagging finger) but rather for us to ponder the relationship between justification and our beliefs. And consider this before we could make claims about metaphysics.
Responses to Descartes
Descartes himself sets up a distinction which runs clearly through many of the responses to his argument. What two kinds of knowledge does he distinguish? (knowledge through the senses, and knowledge from abstract reasoning). Descartes himself comes down on the side of the latter. He uses a thought experiment with wax to show how we are capable of abstraction - an ability which seems to show to him the powers of rational thought. We could imagine everything brought to us by sense being changed, nevertheless we could identify this as the same piece of wax (an intuition of the mind). This is a position of the rationalist.
Rationalists
Rationalists (continental philosophers) agreed with Descartes that logic and math were the models for true knowledge. They felt that all valid knowledge claims rested on the powers of human reason.
Empiricists
Empiricists (British philosophers) disagreed with Descartes and felt that all knowledge comes through the senses. This lead them to a skeptical position in which the felt that no knowledge could meet Descartes certainty criteria. For the empiricists, reason played a role of organizer, not the role of a producer of new knowledge.
Note that we are mostly dealing with the problems of certainty and skepticism. Epistemology, however, is far more vast that this. In fact, it is often broken into sub-divisions of certainty, identification of kinds, justification conditions, truth conditions, belief conditions, and skepticism. We are only touching a small part of epistemology, and only in a superficial manner.
Liebniz
Descartes had offered psychological tests of truth and certainty, Liebniz offered logical criteria. He proposed that the law of contradiction (both a statement and its opposite can not be true) along with the law of excluded middle (a v ~a) is a means to discovering some kinds of truth. He called these truths of reasoning (note: LEM is not accepted by intuitionists). Truths that cannot be so justified are called truths of fact. This second kind of truth can only be established by positing a God - through the principle of sufficient reason. Did you understand Leibiniz's piece from the monadology?
The tradition of logic had long been associated with philosophy (Aristotle was its inventor) and was the basis for the rationalist claims to certain through reason. Truths of logic are rather compelling, and do not seem to rely on sensory experience for the compellingness - they are, in fact, all tautologies. We need few axioms to get a great many claims. (Short history of logic - Aristotle (& early Hindus), syllogism, Kant presumed it was finished, turn of 20th century new boon, symbolic = sentential + predicate, principia mathematica, set theory, arithmetic, nonmonotonic/fuzzy, boolean ('just an exercise'), logic as the way we think & the way we should think).
Hume
Hume followed in the footsteps of Locke by examining the source of our knowledge rather than just the knowledge claims directly. Locke's theory of the tabula rasa (blank slate, usually wax) was intended as an analogy to the state of an infants mind. It is experience that fills the slate up with the materials of knowledge. What does this kind of theory do to our conception of God? (it render's 'God' meaningless) What is wrong with the anti-religious argument? (But we have a concept of God, where does that come from? If we can show there to be an idea there, then tabula rasa is false - reductio ad absurdum. So one thing must give why not tabula rasa?).
Hume took Locke's ideas and made them explicit in his creation of a Newtonian description of mind. What were the 3 main components to his theory?
What are some examples of each of these categories? What examples show the differences that Hume is claiming? What do you think of this analysis? Are there any assumptions Hume is making that aren't explicit?
What does Hume go on to do with this simple theory? (wipes out metaphysics, natural science, and common sense beliefs about the world). How? He attacks our notion of causation. He says no one ever proves that all things must have a cause, they just assume it. But, Hume's powers of doubt are greater than those who hold this position seem to suspect. By applying his theory he thinks we should be able to find such a proof - if it exists. He thinks that we are looking for unalterable relations between ideas, and hope to find causation there (among resemblance, proportions, etc.). However, he claims we can't prove the necessity of causes. Why? He says we can clearly think of things popping in and out of existence without a cause; because this is conceivable, it is actually possible and does not imply a contradiction. Because there is no contradiction, we cannot refute this separation from our ideas. (Notice the structure of his argument... thesis, argument, possible refutations and replies). Why is this denial of causality so important? (so many beliefs are causal, we (and science) assume causal connections to make predictions).
Kant's resolution of the debate
Kant, about a hundred or so years after the debate had begun, attempted a resolution which would dissolve the strong skepticism of the British empiricists. He began similarly to Descartes by positing: "I am conscious". Now Wolff tells us that "introspection reveals and logical analysis confirms" that my consciousness is unified. However, some prominent philosophers of mind believe that this is demonstrably wrong (Dennett). Keep this in mind as we evaluate Kant's discussion. Kant states his starting premise as: "It must be possible for the "I think" to accompany all my representations."
Kant argued that this unity could not be given by experience but must rather be derivative of the mind itself, by its very composition or nature. This identification of a pre-experiential nature of mind Kant divided into several categories. These were ways the mind worked, fundamental rules it followed for unifying experience. For Kant, these categories include things like cause (and effect, unity, plurality, possibility, etc). This is a transcendental argument, and it shows the impossibility of life as an endless dream - by positing something about reality. In fact, Kant denies Descartes' claim that subjective knowledge is primary. Kant says we need the categories before we can have subjective knowledge.
What is the price of this argument? (We can never see things in themselves) Why? (The categories are our innate filters).
Contemporary debates and virtual reality
Brains in vats. What do you think? What do you think of Dennett's attack? How does Coyne's view of the development of virtual reality strike you? How does it relate to the chapter on the philosophy of art?
1) Read pp. 350-562 and pp. 377-386 2) What other parts of philosophy does the relation between theory and observation relate to? Why? 3) What shortcomings are there of the scientific method?