http://www.dspace.cam.ac.uk:80/handle/1810/221775 Mon, 20 May 2013 00:25:36 GMT 2013-05-20T00:25:36Z http://www.dspace.cam.ac.uk:80/handle/1810/237244 Title: Could consciousness be physically realised? Authors: Boutel, Adrian Abstract: I defend physicalism about phenomenal consciousness against recent epistemic arguments for dualism. First I argue (as against Kripke) that psychophysical identities can be a posteriori (and apparently contingent, and conceivably false). Their epistemic status is due to the analytic independence of phenomenal and physical-functional terms. Unlike Kripke’s own explanation of a posteriori necessity, analytic independence is consistent with—indeed explained by—the direct reference of phenomenal terms, so Kripke’s argument against psychophysical identities fails. I then argue (as against White and Chalmers) that direct reference does not itself make identities a priori. Next I endorse the “a priori entailment thesis”: if physicalism is true, phenomenal truths follow a priori from a complete statement of the facts of physics. I argue that physicalists must accept a priori entailment if we are to avoid brute or “strong” a posteriori necessities. I show that a priori entailment is consistent with analytic independence, and so make room for what Chalmers calls “type-C” physicalism. Jackson’s “Mary”, who knows all the physical facts, would be able to deduce the physical-functional reference of phenomenal terms, and so the truth of psychophysical identities, without appealing to analytic connections. The “knowledge” argument for dualism therefore fails. The lack of such connections does, however, help explain why Mary’s deduction seems intuitively impossible. A priori entailment makes zombie scenarios inconceivable, so Chalmers’s “conceivability” argument fails. It also closes Levine’s “explanatory gap” between physical and phenomenal truths. Though it may not satisfy all demands for explanation, any remainder poses no threat to physicalism. I then defend type-C physicalism against some recent objections to the “phenomenal-concept strategy”. I close by observing that while the view I defend can rebut epistemic arguments for dualism, it leaves the question of whether consciousness has a physical basis as a matter for empirical investigation. Tue, 15 Mar 2011 00:00:00 GMT http://www.dspace.cam.ac.uk:80/handle/1810/237244 2011-03-15T00:00:00Z http://www.dspace.cam.ac.uk:80/handle/1810/236596 Title: Essential properties: analysis and extension Authors: Wildman, Nathan Abstract: This thesis is an attempt to understand the essential properties of concrete objects. The underlying motivation of this investigation is the hope that by understanding essential properties we will be in a better position to construct a satisfactory metaphysical account of the things that populate the world around us. The initial chapter introduces two questions that this thesis will attempt to answer. The first, ‘what are essential properties?’ is the Analysis Question. Answering it occupies chapters two through five. The second, ‘what essential properties are there?’ is the Extension Question. This is dealt with in the final three chapters. Chapter two provides the beginnings of an answer to the Analysis question, introducing the modal analysis of essential properties. Eight ways modality and essentiality might be related are raised. Of these, two entail the modal analysis. By eliminating the undesirable six, justification for the modal analysis could be provide. In the remainder of the chapter, five of the six are quickly dismissed. Chapter three is an examination of Fundamentalism. Focusing upon the views of E.J. Lowe and Kit Fine, I argue that there are modal facts which cannot be grounded upon essence facts and that certain modal concepts are employed in the construction of the Fundamentalist account. Consequently, Fundamentalism cannot succeed in grounding modality, and therefore cannot be the correct way to understand essentiality. This concludes the argument by elimination, thereby justifying accepting the modal analysis. Chapter four explores the modal analysis. After distinguishing between various formulations, it is argued that an existence-dependent version of the modal analysis is best. An objection by McLeod concerning contingent existence and essential properties is then dealt with, setting the stage for a more troubling objection from Kit Fine. Fine argues that all forms of the modal analysis ‘get the essential properties wrong’, relying upon a series of example properties, including the relation between Socrates and {Socrates}. After breaking down Fine’s argument, the remainder of the chapter concerns examining and dismissing several bad responses to Fine’s argument, including attempts by Della Rocca and Gorman. In chapter five I advance a new response to Fine which centres upon appealing to the sparse/abundant property distinction. Incorporating this distinction into the modal criteria, I demonstrate that a form of the modal analysis can avoid Fine’s attack. I then conclude that this suitably modified modal analysis is an excellent answer to the Analysis Question. The remaining three chapters are part of an attempt to answer the Extension Question. Chapter six critically examines Wiggins’ sortal essentialism, the position that objects are essentially instances of their sorts. After rendering Wiggins’ essentialist argument, I demonstrate that it is either inconclusive or question begging. As such, there is no reason to accept sortal essentialism. Chapter seven looks at the Byzantine arguments concerning origin essentialism. It is shown that these arguments are either inconclusive - in that they do not entail origin essentialism - or assume origin essentialism at the out-set, leaving us little reason to accept origin essentialism. Chapter eight examines Mackie’s minimalist essentialism. After laying out the position, I then examine a series of objections it faces. In particular, I show that even if we accept minimalist essentialism, it would not help us answer the Extension Question. As such, we have no reason to do so. I conclude that essential properties can best be understood as those sparse properties of an object which satisfy a specific modal criterion, as demonstrated in chapter five. However, the number of properties that satisfy this criterion might be quite small, as indicated by the results of chapters six through eight. This result is a mixed one for the essentialist: while we now know what essential properties are, it seems like we lost them all somewhere along the way. Tue, 11 Jan 2011 00:00:00 GMT http://www.dspace.cam.ac.uk:80/handle/1810/236596 2011-01-11T00:00:00Z http://www.dspace.cam.ac.uk:80/handle/1810/226754 Title: Philosophical aspects of chaos: definitions in mathematics, unpredictability, and the observational equivalence of deterministic and indeterministic descriptions Authors: Werndl, Charlotte Abstract: This dissertation is about some of the most important philosophical aspects of chaos research, a famous recent mathematical area of research about deterministic yet unpredictable and irregular, or even random behaviour. It consists of three parts. First, as a basis for the dissertation, I examine notions of unpredictability in ergodic theory, and I ask what they tell us about the justification and formulation of mathematical definitions. The main account of the actual practice of justifying mathematical definitions is Lakatos's account on proof-generated definitions. By investigating notions of unpredictability in ergodic theory, I present two previously unidentified but common ways of justifying definitions. Furthermore, I criticise Lakatos's account as being limited: it does not acknowledge the interrelationships between the different kinds of justification, and it ignores the fact that various kinds of justification - not only proof-generation - are important. Second, unpredictability is a central theme in chaos research, and it is widely claimed that chaotic systems exhibit a kind of unpredictability which is specific to chaos. However, I argue that the existing answers to the question "What is the unpredictability specific to chaos?" are wrong. I then go on to propose a novel answer, viz. the unpredictability specific to chaos is that for predicting any event all sufficiently past events are approximately probabilistically irrelevant. Third, given that chaotic systems are strongly unpredictable, one is led to ask: are deterministic and indeterministic descriptions observationally equivalent, i.e., do they give the same predictions? I treat this question for measure-theoretic deterministic systems and stochastic processes, both of which are ubiquitous in science. I discuss and formalise the notion of observational equivalence. By proving results in ergodic theory, I first show that for many measure-preserving deterministic descriptions there is an observationally equivalent indeterministic description, and that for all indeterministic descriptions there is an observationally equivalent deterministic description. I go on to show that strongly chaotic systems are even observationally equivalent to some of the most random stochastic processes encountered in science. For instance, strongly chaotic systems give the same predictions at every observation level as Markov processes or semi-Markov processes. All this illustrates that even kinds of deterministic and indeterministic descriptions which, intuitively, seem to give very different predictions are observationally equivalent. Finally, I criticise the claims in the previous philosophical literature on observational equivalence. Tue, 09 Feb 2010 00:00:00 GMT http://www.dspace.cam.ac.uk:80/handle/1810/226754 2010-02-09T00:00:00Z http://www.dspace.cam.ac.uk:80/handle/1810/226320 Title: A defence of predicativism as a philosophy of mathematics Authors: Storer, Tim Abstract: A specification of a mathematical object is impredicative if it essentially involves quantification over a domain which includes the object being specified (or sets which contain that object, or similar). The basic worry is that we have no non-circular way of understanding such a specification. Predicativism is the view that mathematics should be limited to the study of objects which can be specified predicatively. There are two parts to predicativism. One is the criticism of the impredicative aspects of classical mathematics. The other is the positive project, begun by Weyl in Das Kontinuum (1918), to reconstruct as much as possible of classical mathematics on the basis of a predicatively acceptable set theory, which accepts only countably infinite objects. This is a revisionary project, and certain parts of mathematics will not be saved. Chapter 2 contains an account of the historical background to the predicativist project. The rigorization of analysis led to Dedekind's and Cantor's theories of the real numbers, which relied on the new notion of abitrary infinite sets; this became a central part of modern classical set theory. Criticism began with Kronecker; continued in the debate about the acceptability of Zermelo's Axiom of Choice; and was somewhat clarified by Poincaré and Russell. In the light of this, chapter 3 examines the formulation of, and motivations behind the predicativist position. Chapter 4 begins the critical task by detailing the epistemological problems with the classical account of the continuum. Explanations of classicism which appeal to second-order logic, set theory, and primitive intuition are examined and are found wanting. Chapter 5 aims to dispell the worry that predicativism might collapses into mathematical intuitionism. I assess some of the arguments for intuitionism, especially the Dummettian argument from indefinite extensibility. I argue that the natural numbers are not indefinitely extensible, and that, although the continuum is, we can nonetheless make some sense of classical quantification over it. We need not reject the Law of Excluded Middle. Chapter 6 begins the positive work by outlining a predicatively acceptable account of mathematical objects which justifies the Vicious Circle Principle. Chapter 7 explores the appropriate shape of formalized predicative mathematics, and the question of just how much mathematics is predicatively acceptable. My conclusion is that all of the mathematics which we need can be predicativistically justified, and that such mathematics is particularly transparent to reason. This calls into question one currently prevalent view of the nature of mathematics, on which mathematics is justified by quasi-empirical means. Mon, 07 Jun 2010 23:00:00 GMT http://www.dspace.cam.ac.uk:80/handle/1810/226320 2010-06-07T23:00:00Z