June 4 : Metaphysics
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To do for next class - 1) Read pp. 388-405. 2) Are you a materialist? Do you think we are free-willed? 3) What do you think really exists? |
To do for next class - 1) Read pp. 405-423 2) Will computers ever be intelligent? Why, why not? 3) Final papers are due. 4) Final exam worth 15%. |
Introduction
The term metaphysics actually comes from somewhat of an historical accident. Editors of Aristotle's work simply titled the book which comes after his 'physics' the 'metaphysics' - which indeed discusses many of the classic problems of metaphysics - so 'meta' simply means 'after'. Despite Wolff's comments, the dictionary (Webster's) now defines the prefix meta to mean "more comprehensive : transcending -- used with the name of a discipline to designate a new but related discipline designed to deal critically with the original one" and this is how it's often used and is applicable to understanding the term metaphysics (just like meta-ethics). The term has taken on a somewhat mysterious air in pop culture and is used by some to denote a relation to new age mysticism.
What metaphysical questions and positions have we already discussed? (cosmology, ontology, idealism, realism, etc.) Metaphysics is the study of the nature, structure and constitution of reality - sounds almost like a definition of philosophy for some. A major component of metaphysics is ontology, i.e. what there is (matter, sets, null set, experience, minds, relations). Other aspects of metaphysics are questions concerning the nature of time and space (relations, or containers?), what properties all entities share, free will. In ontology, questions concerning the nature of minds has become somewhat of a separate discussion (mind/body relation, dualism, reference, content, individuation) which often overlaps with philosophy of language and more recently philosophy of science.
What metaphysical beliefs do you think you have? Which do you think science has? Christianity? Is metaphysics a waste of time? Why, why not?
What kind of metaphysical questions can you think of? (Does the past exist? Do souls exist? Does the future exist? Do only currently existing things exist? What sorts of things are there? What kinds of relations can they have? What are properties? Are properties and relations real? What is space? Is it a container that things sit in, or is it a relation between things? What is time? Can there be a stretch of time during which nothing occurs? Are there possible worlds? Do they exist? Are my actions free? What about the Laplacian demon? Is the universe absurd or rational? Why is there stuff at all? Was the universe created? Is there a god or gods?)
Hobbes is generally better know as a political philosopher than a metaphysician. His greatest contributions to philosophy were in his work Leviathan, which was concerned with justifying the place of monarchy in politics. However he is also one of the first writers to explicitly endorse the position in metaphysics known as materialism. Materialism is an ontological position, that is, it answers the question "What is there?" - materialism answers "matter, i.e. physical objects". As simple, straightforward and uncontroversial as this answer may seem, it is anything but those. Science, of course has adopted this metaphysical position. But, what of minds, souls, and spirit - consciousness? This is a question that materialists have no compelling answer for (compelling for some, in any case).
Of course Hobbes is not the first materialist we have met both Democritus and Leucippus in previous discussions - the atomists. Hobbes, however, had a more modern view (and no doubt more of his writings survived so we understand the position better) of materialism so he is our representative materialist. Of course, he had no difficultly explaining things - wood, stone, flesh, brains, stars, moons, bone, you name it. As physicists are content to do today, he postulated things (all things) are composed of atoms. So, what's the problem? How would you try to answer this problem?
What is Hobbes answer? Hobbes is convinced that we are complicated machines. Just as Data is from The Enterprise. The episode "measure of a man" is an extended look at whether Data counts as sentient. The conclusion, of course, is yes - so Data is granted rights. Hobbes would hardly be surprised by this conclusion, but are we? Of course, we are surround by Data's ancestors - computers. And, we have no trouble explaining them, and also we have no trouble realizing they are not sentient. The question for materialists is one of prediction - How would we know when they are sentient? What is it about certain complicated machines (us) that distinguish them from other complicated machines (computers)? How do we understand choice, desire, anger, and consciousness such that machines can have all these properties/abilities?
For Hobbes, the answer is that everything we label with terms like 'desire', 'contempt', etc. are explicable in terms of the motion of atoms. We are just big stimulus response machines. When we see food, it triggers our legs and arms to move us towards it. Of course, if the food is bad, the atoms will have the effect of moving us away. If the food is cheesecake, and we are full and watching our weight, we make take a moment and 'decide' - i.e. the atoms cause a vacillation between moving towards or away from the food. What do you think of his descriptions? Of course, we can dress them up with neurophysiological descriptions, but they will essentially be the same. Don't forget, we can explain almost all the behavior of some organisms in this way, why not us? Wolff labels this position a 'troubling' idea. Why?
The most common, and most hotly debated still, objection to the materialist position is the consciousness objection (formulated convincingly by Thomas Nagel in his article "What it is like to be a bat") - recently dubbed the 'hard problem' by David Chalmers a former post doc here. The objection goes like this - we are conscious and nothing else is. Therefore we are unlike machines in this important respect (whether or not we talk about our car 'wanting' to start). Materialism, in principle, can not provide an explanation of the 'emergence' of consciousness from physical matter. Data isn't conscious (nor are zombies). Thus, we are not merely material things. Of course, those who support this position must provide an alternative explanation of consciousness - we start as a zygote, when is consciousness infused? How do we argue against Hobbes without resorting to a religious dogma?
Idealism
Idealism is the complete denial of materialism. Idealism claims that all that exists is mind-stuff. That is, experience, or simply minds themselves. The biggest problem is that of solipsism. The consciousness problem is solved. How do we explain objectivity? The success of science? This is the position of Berkeley. Related problems come up for Kant's transcendental realism and Poincare's phenomenalism.
Dualism
Dualism is the position that was posited in the modern era by Descartes. It is a combination of idealism and materialism. Dualism is dual precisely because it posits the existence of minds and bodies. The problem now becomes one of explaining the relation between the two. This position seems to be the one assumed by Christianity (and perhaps Plato).
We first encountered this problem in the philosophy of the Stoics. Do you recall why it was a problem? Why are so concerned with being free? (responsibility is extremely important to our society's structure). Are you free? Do you make choices? What if you aren't? The consequences of denying free will are catastrophic - maybe I didn't choose to go to college, maybe I didn't choose what clothes to wear this morning or what the topic of my essay was, or etc. etc. What then? Of course I don't choose some things - whether the sun will rise, whether my heart will beat (though we seem to have control over how fast) - and those things I am not responsible for.
But again, Hobbes' position rears up. We know that if we electrically stimulate parts of our brain, our limbs will move, we will even remember certain things. We know that our bodies are controlled by nerves which seem to operate by the laws of physics. Hobbes simply denies free choice. He posits that because the motions of atoms (nerve impulses) are to small to detect we are under the 'illusion' that we are free. Wolff gives us the Gulliver analogy to help us understand this position.
Do Hume's examples (or the examples Wolff gives to Hume) show that we are determined? Is there a difference between determinism and predictability?
What is Kant's reply? Think back to Kant's resolution of the empiricist/rationalist debate. There he distinguishes between our knowledge of the world and how the world really is (things in themselves). He claims to have shown there that reality is filtered by our categories. Of course, all of our scientific theories are based on the outcomes of these filters. And clearly, these theories leave no room for free will. However, that is not all there is. There is also reality (not just the appearance of it to us through our filters), which Kant claims, is non-causal. Thus, our free will is due to the 'rational determination' of the realm of things in themselves.
Read the list off the bottom of p. 392-3 - which of these do you think exist? Which of the previous categories would you put yourself in? Are you prepared to accept all of the consequences of those positions? What are they? Why? Is it important to know what there is?
1) Read pp. 405-423 2) Will computers ever be intelligent? Why, why not? 3) Final papers are due. 4) Final exam worth 15%.