acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

In this dissertation we investigate the following problem in ergodic theory: Let X be a Polish space and T:X→X a homeomorphism. We ask whether there exists a non-atomic Borel probability measure m on X, ergodic and quasi-invariant under T, such that the cohomology class of some preassigned continuous function f:X→S1 is trivial. The cohomology class of f is trivial and f is called a coboundary of T, if the equation hTx=f x˙hx m-almosteverywhere admits a measurable solution h:X→S1 In the presence of a non-periodic recurrent point x0∈X , we establish the existence of such a measure m . Indeed, our approach, which is based on a construction of Katznelson and Weiss, yields a continuum of such measures all of which are of type IIinfinity and pointwise orthogonal. And the same statement is true for measures of type III / acase@tulane.edu

This essay argues for three theses. The first is that the notion of agent-neutral value, or more accurately, the promotion of agent-neutral values, is what truly defines consequentialism as a type of moral theory. A state of affairs is of agent-neutral value if it is capable of generating reasons for action for everybody. The second is that the existence of agent-neutral value has never been proven, and no known account of this notion has made clear what kind of things these are. In particular, I argue that both the non-moral approach and the moral approach to make good the claim about the existence of agent-neutral values are unable to deliver the desired results. The third thesis is that moral philosophy should exorcise the notion of agent-neutral value, not only because we do not know what type of things these are, but also because we do not need this notion in order to have good moral philosophy. I offer, basically, two arguments here. One is that when the justificatory issue is properly formulated, the so-called 'agent-relative rules' appear to be justifiable. The other is that the duty of beneficence can be accounted for on grounds other than that of agent-neutral value / acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

During the past twenty-five years, a distinct philosophical discipline has emerged which is devoted to a normative analysis of the relation between humanity and the nonhuman natural world. This discipline has come to be known as 'environmental ethics.' The most recent, as well as most radical approach to environmental ethics is known as ecocentrism. The ecocentric approach to environmental ethics uses an 'eco-holistic' perspective as its ontological ground, and attempts to use such a perspective to argue for an axiological stance which affirms the inherent value of nonhuman nature, as well as a normative theory, based on the 'fact' that humans are simply 'plain citizens' of ecosystemic communities, which asserts that humanity is morally obligated to preserve the integrity and stability of the ecosphere and its component ecosystems I argue that the use of ecological modeling to generate the ontological ground of ecocentric environmental ethics creates serious problems for the subsequent axiological and normative claims made by ecocentrists. In particular, my critique of ecocentrism is advanced on two major fronts. First, I attempt to argue that, since an 'eco-holistic' perspective grants to ecosystems an ontological standing independent of that of their constitutive parts (both biotic and abiotic), ecocentric axiological claims to the effect that both ecosystems and individual organisms are inherently valuable can be seen as conflicting in that preserving ecosystemic inherent value may, in certain common situations, demand the elimination of loci of organismic inherent value. Further, I argue that ecocentrists have no way to settle the moral dilemma that emerges from this axiological dilemma On the second front, I attack the crucial premise that humans are 'plain citizens' of ecological communities by using ecological modeling itself to show that, contrary to what ecocentrists claim, humans do not, for the most part, participate in ecosystems or biotic communities in an ecologically defined way. Consequently, I argue that since humans are not participants in natural ecosystemic structures, ecocentrists cannot conclude that humans are morally obligated to preserve the integrity and stability of natural ecosystems as a consequence of their inclusion in such 'communal' structures / acase@tulane.edu