The metaphysics of mental causation

This thesis argues that the fundamental issues within the mental causation debate are metaphysical ones. Consequently, it is only with metaphysical clarity, that any clarity can be gained in the mental causation debate. In order to provide a successful theory of mental causation one cannot divorce oneself from metaphysics. Neither can one hope to provide a theory of mental causation that is somehow neutral between the various metaphysical systems. Rather, to be plausible, a theory of mental causation must be based within an independently plausible metaphysical framework. I divide the metaphysical issues that are of importance to the mental causation debate into three broad groups. Firstly, what causation is a relation between. Secondly, what the existence and identity conditions for properties are. Thirdly, what the causal relation is. Part One of this thesis is concerned with the first of these issues. The interpretation of the argument from causal over determination, and the possible responses to it, depend upon what causation is a relation between. A belief to the contrary, has led to implausible theories of mental causation and the misrepresentation of those positions within the mental causation debate that are ontologically serious. Part Two is concerned with property analysis. It is suggested that a plausible analysis of properties reveals that the true contenders within the mental causation debate are psychophysical reductionism on the one hand, and interactive mentalism on the other. Part Three is concerned with the causal relation. It is argued that the mental causation debate is affected by what one understands causation to be. In particular, whether a causal closure principle that is strong enough to allow one to advance physicalism can plausibly be advanced, depends upon the theory of causation in which one is embedding psychophysical causation

Intrinsic Information carriers in combinatorial dynamical systems

International audienceMany proteins are composed of structural and chemical features—“sites” for short—defined by definite inter- action capabilities, such as non-covalent binding or covalent modification of other proteins. This modularity allows for varying degrees of independence, as the behavior of a site might be controlled by the state of some but not all sites of the ambient protein. Independence quickly generates a startling combinatorial complexity that characterizes most biological networks, such as mammalian signaling systems, and effectively prevents their study in terms of kinetic equations—unless the complexity is radically trimmed. Yet, if combinatorial complexity is key to the system's behavior, eliminating it will prevent, not facilitate, understanding. A more adequate representation of a combinatorial system is afforded by a graph-based framework of rewrite rules where each rule specifies only the information that an interaction mechanism depends on. Unlike reactions, rules deal with patterns, i.e. sets of molecular species, rather than molecular species themselves. Although the stochastic dynamics induced by a set of rules on a mixture of molecules can be simulated, we aim at capturing the system's average or deterministic behavior. However, expansion of the rules into differential equations at the level of molecular species is not only impractical, but conceptually indefensible. If rules describe patterns of interaction, fully-defined molecular species are unlikely to constitute appropriate units of dynamics. Rather, we must seek aggregated variables reflective of the causal structure laid down by the mechanisms expressed by the rules. We call these variables “fragments” and the process of identifying them “fragmentation”. Ideally, fragments are aspects of the system's microscopic population that the set of rules can actually distinguish on average; in practice, it may only be feasible to identify an approximation to this. Most importantly, fragments are self-consistent descriptors of system dynamics in that their time evolution is governed by a closed system of kinetic equations. Taken together, fragments are endogenous distinctions that matter for the dynamics of a system, and this warrants viewing them as the carriers of information. Although fragments can be thought of as multi-sets of molecular species (an extensional view), their self-consistency suggests treating them as autonomous aspects cut off from their microscopic anchors (an intensional view). Fragmentation is a seeded process and plays out depending on the seed provided, which leaves open the possibility that different inputs cause distinct fragmentations, in effect altering the set of information carriers that govern the behavior of a system, even though nothing has changed in its microscopic constitution. We provide a mathematical specification of fragments, but not an algorithmic implementation. We have done so elsewhere in rather technical terms with specific biases that, although effective, were lacking an embed- ding into a more general conceptual framework. Our main objective in this contribution is to provide that framework

Paths in first language acquisition: Motion through space in English, French and Japanese

This thesis examines how children attain the linguistic knowledge they need to grammatically express basic trajectories through physical space in English, French and Japanese. In Talmy's (1991; 2000b) descriptive binary typology, 'verb-framed’ languages such as Japanese and French systematically encode PATH (or 'direction') in verbs, whilst 'satellite-framed' languages such as English systematically do so in adpositions. How such phenomena might be formalized is considered in terms of two contrasting hypotheses: (i) the Path Parameter Hypothesis, which suggests binary parameterization at the whole-language level, and (іі) the Lexicalist Path Hypothesis, which suggests that all relevant aspects of PATH predication are determined at the level of individual lexical items. Two experiments with original research methodology were conducted with English, French and Japanese children and adults. In Experiment I, directional predicates were elicited using a purpose-designed picture-story, and in Experiment II, grammaticality judgements were elicited from the same test subjects. Whilst predictions of general tendencies were upheld (strongly for English and Japanese, weakly for French), several findings support a non-parameterized, lexicalist account of PATH predication. First, in all child age groups, the three languages fell into discrete response categories for directional utterances in the absence of an inherent PATH verb. Second, both lexicalization types were found in each language, again in all age groups. Third, the three languages are revealed to have a shared syntax of directional predication, involving the same set of interpretable features and the same set of basic syntactic structures, including a layered pp structure. These findings suggest that whilst the typology remains broadly descriptive, there is no language-particular grammar involved in this variation. Rather, both directional V and a fully articulated pp structure are available in all three languages, show no discernable development, and are presumably part of the machinery of Universal Grammar. Children already understand the syntactic possibilities in the predication of PATH, but must learn the particular complexities of their lexicon, the primary locus of variation in the linguistic expression of motion events

A geochemical study of a layered portion of the Horoman peridotite, Southern Hokkaido, Japan

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmosphere and Planetary Sciences, 1987.Bibliography: v. 2, leaves 260-271.by Alan Edward Leinbach.M.S

Clifford Algebra: A Case for Geometric and Ontological Unification

Robert Batterman’s ontological insights (2002, 2004, 2005) are apt: Nature abhors singularities. “So should we,” responds the physicist. However, the epistemic assessments of Batterman concerning the matter prove to be less clear, for in the same vein he write that singularities play an essential role in certain classes of physical theories referring to certain types of critical phenomena. I devise a procedure (“methodological fundamentalism”) which exhibits how singularities, at least in principle, may be avoided within the same classes of formalisms discussed by Batterman. I show that we need not accept some divergence between explanation and reduction (Batterman 2002), or between epistemological and ontological fundamentalism (Batterman 2004, 2005). Though I remain sympathetic to the ‘principle of charity’ (Frisch (2005)), which appears to favor a pluralist outlook, I nevertheless call into question some of the forms such pluralist implications take in Robert Batterman’s conclusions. It is difficult to reconcile some of the pluralist assessments that he and some of his contemporaries advocate with what appears to be a countervailing trend in a burgeoning research tradition known as Clifford (or geometric) algebra. In my critical chapters (2 and 3) I use some of the demonstrated formal unity of Clifford algebra to argue that Batterman (2002) equivocates a physical theory’s ontology with its purely mathematical content. Carefully distinguishing the two, and employing Clifford algebraic methods reveals a symmetry between reduction and explanation that Batterman overlooks. I refine this point by indicating that geometric algebraic methods are an active area of research in computational fluid dynamics, and applied in modeling the behavior of droplet-formation appear to instantiate a “methodologically fundamental” approach. I argue in my introductory and concluding chapters that the model of inter-theoretic reduction and explanation offered by Fritz Rohrlich (1988, 1994) provides the best framework for accommodating the burgeoning pluralism in philosophical studies of physics, with the presumed claims of formal unification demonstrated by physicists choices of mathematical formalisms such as Clifford algebra. I show how Batterman’s insights can be reconstructed in Rohrlich’s framework, preserving Batterman’s important philosophical work, minus what I consider are his incorrect conclusions

Nonequilibrium Thermodynamics in Biology: From Molecular Motors to Metabolic Pathways

Biological systems need to exchange energy and matter with their environment in order to stay functional or “alive”. This exchange has to obey the laws of thermodynamics: energy cannot be created and exchange comes at the cost of dissipation, which limits the efficiency of biological function. Additionally, subcellular processes that involve only few molecules are stochastic in their dynamics and a consistent theoretical modeling has to account for that. This dissertation connects recent development in nonequilibrium thermodynamics with approaches taken in biochemical modeling. I start by a short introduction to thermodynamics and statistical mechanics, with a special emphasis on large deviation theory and stochastic thermodynamics. Building on that, I present a general theory for the thermodynamic analysis of networks of chemical reactions that are open to the exchange of matter. As a particularly insightful concrete example I discuss the mechanochemical energy conversion in stochastic models of a molecular motor protein, and show how a similar analysis can be performed for more general models. Furthermore, I compare the dissipation in stochastically and deterministically modeled open chemical networks, and present a class of chemical networks that displays exact agreement for arbitrary abundance of chemical species and arbitrary distance from thermodynamic equilibrium. My major achievement is a thermodynamically consistent coarse-graining procedure for biocatalysts, which are ubiquitous in molecular cell biology. Finally, I discuss the thermodynamics of unbranched enzymatic chains