The Province of Conceptual Reason: Hegel\u27s Post-Kantian Rationalism

In this dissertation, I seek to explain G.W.F. Hegel’s view that human accessible conceptual content can provide knowledge about the nature or essence of things. I call this view “Conceptual Transparency.” It finds its historical antecedent in the views of eighteenth century German rationalists, which were strongly criticized by Immanuel Kant. I argue that Hegel explains Conceptual Transparency in such a way that preserves many implications of German rationalism, but in a form that is largely compatible with Kant’s criticisms of the original rationalist version. After providing background on Hegel’s relationship to the traditional rationalist theory of concepts and Kant’s challenge to it, I claim that Hegel’s central task is to provide a theory of conceptual content that allows a relationship to the objective world without being dependent on the specifically sensory aspect of the world, which Kant’s theory of concepts required. Since many interpreters deny that Hegel’s use of the term “concept” is comparable to other historical philosophers (or our own), I first show that Hegel’s critique of standard conceptions of concepts presupposes an agreement of subject matter. I then show how Hegel’s account of the “formal concept” provides the skeleton for a view of conceptual content that relies on negative relations between terms, rather than a relation to sensibility, to provide content. Hegel’s account of conceptual content is completed when he shows how a universal term is further specified so that it can determine singular objects. This occurs in its adequate form in a teleological process. I argue that Hegel’s account of teleology in the Science of Logic is an attempt to explain how and where Conceptual Transparency obtains. A teleological process is one in which a concept constitutes an object, and this means that a concept is perfectly adequate to express that thing’s nature and not merely to represent it. However, in the final chapter, I show that Hegel’s concept of teleology is meant paradigmatically to illuminate how human purposive processes have constituted a social world that is conceptually accessible to us. In this way, the primary “province” of Hegel’s rationalism is the human constructed world

The Authority of Conceptual Analysis in Hegelian Ethical Life

While the idea of philosophy as conceptual analysis has attracted many adherents and undergone a number of variations, in general it suffers from an authority problem with two dimensions. First, it is unclear why the analysis of a concept should have objective authority: why explicating what we mean should express how things are. Second, conceptual analysis seems to lack intersubjective authority: why philosophical analysis should apply to more than a parochial group of individuals. I argue that Hegel’s conception of social ontology, focused on his concept of “ethical life” (Sittlichkeit), helps to explain how concepts (and their explication) have both objective and intersubjective authority in the social domain. Hegel claims that modern institutions are the product of self-conscious purposes, so that they are conceptually constituted. Concepts do not just represent these objects and so depend on a contingent relation to them. As many contemporary social ontologists agree, this means that our concepts of these institutions are uniquely epistemically “transparent.” They have objective authority. Concepts have intersubjective authority in the modern world as well, according to Hegel. However, I show that this feature of Hegel’s account does not rely on the solution to a philosophical problem. Rather, since the concepts of modern ethical life are “essentially contested,” their content depends on the practical and political agreement of modern subjects. This means that concepts can only have objective authority if some prior intersubjective agreement has been reached. The role of philosophy as conceptual analysis is thus importantly dependent on political developments

INTERACTIONS AMONG CLIMATE, FIRE, AND ECOSYSTEM PROCESSES ACROSS MULTIPLE SPATIAL AND TEMPORAL SCALES IN ROCKY MOUNTAIN FORESTS

Warmer and drier climate conditions over recent decades are contributing to widespread increases in fire activity across western North America. The combined impacts of changing climate and fire activity threaten to undermine the longstanding resilience of forest ecosystems to wildfires, potentially leading to ecological transformations. This context creates a pressing need to understand the direct effects of climate and wildfire on ecosystem processes, and how longer-term changes in climate, fire activity, and ecosystem processes interact to determine ecological trajectories. This dissertation advances our understanding of the causes and ecosystem consequences of wildfire and changing fire regimes in northern Rocky Mountain forests over years to millennia. In Chapter 1, I utilized extensive field sampling in two recent wildfires in western Montana to document how fires alter microclimatic conditions in biologically meaningful ways for regenerating and surviving vegetation. Through a subsequent study that tracked conifer seedling demography over the first three years following these wildfires, Chapter 2 highlights how spatial heterogeneity in fire effects can facilitate tree regeneration following wildfires, provided suitable post-fire climate. Overall, forests are exhibiting early signs of resilience to these two fire events. Chapters 3 and 4 utilized paleoecological methods to address questions of long-term ecosystem change, and relationships among climate, fire activity, and ecosystem processes. In Chapter 3 I used a high-resolution, multiproxy lake-sediment record from the northern Rockies to reconstruct fire activity and ecosystem change over the past 4800 years. Changes in vegetation and fire activity coincident with increased effective moisture c. 2000 years ago highlight the overarching impact of climate on shaping ecosystem processes. Past wildfires had diverse, detectable impacts on biogeochemical processes, and evidence of ecosystem resilience to wildfires was consistent across variations in climate, vegetation, and fire activity over the late Holocene. Chapter 4 addressed variability in fire activity across a broader landscape, much of it burned during the historic 1910 fire season. I developed a network of 12 lake-sediment records to reconstruct a landscape-scale fire history over the past 2500 years and quantify the historical range of variability. This perspective reveals that contemporary burning, including the 1910 fires, remains within the historical range of fire activity in subalpine forests in this region. My findings imply that northern Rocky Mountain subalpine forests are currently experiencing fire activity and ecological dynamics broadly consistent with historical variability. However, each chapter also highlights the sensitivity of multiple forest ecosystem processes to climate conditions and climate variability. Given the rapid rate of ongoing climatic change, subalpine forests will become increasingly vulnerable to widespread shifts in composition and structure. Future research could focus on identifying thresholds to change and early warning signals

Multiple scattering of polarized radiation by non-spherical grains: first results

We present the first numerical radiative transfer simulation of multiple light scattering in dust configurations containing aligned non-spherical (spheroidal) dust grains. Such models are especially important if one wants to explain the circular polarization of light, observed in a variety of astronomical objects. The radiative transfer problem is solved on the basis of the Monte Carlo method. Test simulations, confirming the correct numerical implementation of the scattering mechanism, are presented. As a first application, we investigate the linear and circular polarization of light coming from a spherical circumstellar shell. This shell contains perfectly aligned prolate or oblate spheroidal grains. The most remarkable features of the simulated linear polarization maps are so-called polarization null points where the reversal of polarization occurs. They appear in the case when the grain alignment axis is perpendicular to the line of sight. The maps of circular polarization have a sector-like structure with maxima at the ends of lines inclined to the grain alignment axis by \pm 45\degr.Comment: 13 pages, 14 figures, accepted by A&

Supersymmetric Noether Currents and Seiberg-Witten Theory

The purpose of this paper is twofold. The first purpose is to review a systematic construction of Noether currents for supersymmetric theories, especially effective supersymmetric theories. The second purpose is to use these currents to derive the mass-formula for the quantized Seiberg-Witten model from the supersymmetric algebra. We check that the mass-formula of the low-energy theory agrees with that of the full theory (in the broken phase).Comment: 30 pages, LaTe