This course will survey some major topics in metaphysics: free will and determinism, causation and laws, possibility and possible worlds, natural kinds, and personal identity over time.
Metaphysics is the study of the ultimate nature of reality. Unfortunately, this cryptic formulation is nearly useless. One can simply delve into metaphysics to learn what it is; but perhaps a bit more can be said beforehand.
Think of metaphysics as involving theory and location. Metaphysics aspires to give a comprehensive theory of reality. Such a theory will include an ontology, a theory of what exists, as well as an ideology, a specification of the sorts of things we can say about the objects in the ontology. As for location, since the theory is supposed to be comprehensive, we investigate where (and whether) the things in which we ordinarily believe can be located in the theory.
The search for a comprehensive theory often leads to the following dilemma. For one reason or another, metaphysicians often propose a fairly meager metaphysics, a theory with a slender ontology or ideology. It can then be difficult to fit all of the elements of our everyday conceptual scheme into this meager metaphysics. Perhaps we have left no room for persons, or thought, or ordinary physical objects! Faced with this dilemma, a particularly severe metaphysician might become an eliminativist; she might choose to follow her theory and claim that there simply are no persons, thoughts, or ordinary physical objects. Alternatively, she might be a reductionist, and claim that there is room after all for persons, thoughts and ordinary physical objects in her metaphysical theory, provided one accepts an appropriate understanding of what persons, thoughts and ordinary physical objects are. A final option is antireductionist: one can give up the theory responsible for the dilemma in favor of a richer theory in which the elements of our ordinary conceptual scheme may be located.
The problem of free will and determinism is that of integrating a belief most of us have, that people sometimes act freely and are morally responsible for what they do, with a scientific picture of the world that most of us also accept, according to which any person's actions have causes that lie beyond his or her control. This is an instance of the sort of dilemma mentioned in the previous paragraph; accordingly the literature on free will contains instances of the eliminativist, reductionist and antireductionist responses. Eliminativists about free will are known as "hard determinists"; they say that free will does not exist. Reductionists are called "compatibilists"; they recommend reinterpreting free will so that it does not conflict with the scientific picture. The antireductionists are the "libertarians", who advocate giving up part of the scientific picture in order to make room for free will.
The problem of laws and causation is finding room for causal notions in our overall theory of the world. Causal notions involve a certain kind of necessity -- an object dropped does not merely happen to fall; it must fall; its falling is causally necessary, given that it was dropped. Philosophers typically distinguish two causal notions: laws of nature and causation. Laws of nature are general patterns scientists seek to formulate, whereas statements of causation concern particular events: we say that this striking of a match caused this event of the match lighting. The core question here is what the necessity of laws and causation amounts to.
The topic of possibility and necessity concerns necessity of a different, broader sort. Though it is a law of nature that dropped objects fall, we can imagine a world in which this does not happen; the laws of nature could have been different. In a broader sense, then, it is not necessary that dropped objects fall. What is necessary in this broader sense? Alleged examples of necessary truths include 'all bachelors are unmarried', 'No one is taller than himself' and 'Ted is human'. We will investigate what it is for a proposition to be necessary, and whether necessity attaches only to propositions (de dicto necessity) or to things as well (de re necessity).
Humans group some objects together as similar, and consider others dissimilar. Do these groupings reflect genuine similarities in nature, or merely human interests? What are the ramifications elsewhere of giving either answer? This is the problem of natural kinds.
Our final topic, personal identity, concerns the continued existence of persons over time. We ordinarily assume that persons continue to exist over time -- that the very same person that existed in the past is present before us now. Otherwise it would make no sense to blame persons for their past acts or to plan for the future. And yet, persons change over time, both psychologically (we accumulate memories and our characters change) and physically (the body periodically recycles its matter). Moreover, we think of some changes as resulting in the destruction of the person: imagine the "change" that occurs in a person when her body is vaporized by a bomb. So: in what does continuing over time consist, and what is the difference between changes a person survives and changes that destroy?
Metaphysics includes many other topics we will not have time to investigate, for example the philosophy of time and space (ontology of the past and future; tense; direction of time; substantivalism); persistence over time (artifact identity, material constitution); other topics concerning causation and laws of nature (events, states of affairs, the nature of chance); other topics involving possibility and possible worlds (counterfactuals, supervenience, two-dimensionalism, essentialism); realism/antirealism; truth; Sellars manifest image/Jackson's placement problem (color); ontology (abstract entities, mereology, meta-ontology).
Libertarianism Chisholm, "Human Freedom and the Self" (W); Clarke, "Toward a credible agent-causal account of free will"
Soft determinism/compatibilism Ayer, "Freedom and Necessity" (W); Frankfurt, "Freedom of the Will and the Concept of a Person" (W)
Incompatibilism Peter van Inwagen, "The Incompatibility of Free Will and Determinism" (W); Lewis, "Are We Free to Break the Laws?"
Quine "Two Dogmas of Empiricism", "Reference and Modality", both in From a Logical Point of View
Kripke Naming and Necessity
Lewis On the Plurality of Worlds 1.1-1.2, 1.6-1.9; chapter 2; 4.1, 4.4-4.5.
Regularity theory of laws Armstrong, What is a Law of Nature?, chapters 1-5; Lewis, Counterfactuals pp. 73-74; Lewis, Philosophical Papers, vol 2, pp. 121-124; Lewis, "Humean Supervenience Debugged"
DTA theory of laws Armstrong, What is a Law of Nature?, chapters 6-8; Lewis, introduction to Philosophical Papers, vol 2., p. xii; van Fraassen, Laws and Symmetry, pp. 94-103.
Laws are necessary Shoemaker, "Causal and Metaphysical Necessity"
Skepticism about laws Van Fraassen, Laws and Symmetry, part II.
Covering law analysis of causation Mackie, "Causes and Conditions" (S&T)
Counterfactual theory of causation Lewis, "Causation (S&T) (plus postscripts from Philosophical Papers, vol 2.
Primitivism about causation Anscombe, "Causality and Determination" (S&T)
Causation and probability Christopher Hitchcock, ???
Eliminativism Quine, "Natural Kinds"
Anti-reductionism Putnam, "On Properties", Lewis, On the Plurality of Worlds pp. 59-69; Lewis, "New Work for a Theory of Universals"
Body theory Introduction to Perry, Personal Identity; Shoemaker & Swinburne, Personal Identity, pp. 1-8.
Memory theory S&S, pp. 8-13; Thomson, "People and their bodies"
Duplication problem S&S, pp. 13-21; Lewis, "Survival and Identity"
Dualism S&S, pp. 22-34; 49-66.