This dissertation collects five papers that discuss potential consequences of the defeasibility of knowledge. Chapters 1, 2, 3, and 5 provide arguments for a number of important epistemological consequences of the defeasibility of knowledge. Chapter 4 discusses consequences that others have claimed the defeasibility of knowledge to have. Chapter 1 argues that closure principles for knowledge are in tension with the defeasibility of knowledge. Chapter 2 argues that one of Williamson's famous arguments against the KK principle relies in a problematic way on a closure principle that is incompatible with defeat. Chapter 3 argues that a view on which knowledge just is belief safe from error is in tension the defeasibility of knowledge. Chapter 4 discusses two arguments to the effect that defeat by higher-order evidence sometimes involves the violation of rational ideals or rules of rational belief formation. As part of a response to an objection to contextualism about 'know', Chapter 5 investigates a number of social epistemological consequences of the defeasibility of knowledge.

The Cradle of Humankind, famous for its abundance of hominid fossils, has been preserved as a pristine landscape throughout the modern era, thanks to the establishment of the site as a natural and cultural World Heritage Site in 1994 (Maropeng 2016). In this dissertation the complexity surrounding a world heritage hominid fossil site is investigated. Kromdraai Cave, one of the five original caves included in the World Heritage declaration on the Cradle of Humankind, is investigated as a point of connection between conflicting values within the world heritage context. Through the intervention the site is envisioned as connecting not only the values of the world heritage site, but also providing an understanding of the landscape as a whole. The site is envisioned as a centre of knowledge, relating the value of the site directly to the context. The distribution of knowledge will allow the heritage to be accessible, not only to the scientist but also to the community. / Die Wiegvan die Mensdom is bekend vir die oorvloed hominied-fossiele wat daar voorkom, en is dwarsdeur die moderne era as 'n ongerepte landskap bewaar, danksy die die feit dat dit in 1994 as 'n natuurlike en kulturele Werelderfenisgebied verklaar is (Maropeng 2016). Hierdie skripsie ondersoek die kompleksiteite wat so 'n hominied-werelderfenisgebied omring. Kromdraai-grot, een van die vyf oorspronklike grotte wat ingesluit is toe Werelderfenisstatus a an die Wieg van die Mensdom toegeken is, word as aansluitingspunt tussen teenstrydige waardes binne 'n werelderfeniskonteks ondersoek. Deur die voorgestelde ingryping word dit moontlik dat die terrein nie aileen 'n verband skep tussen die onderskeie waardes wat 'n werelderfenisgebied verteenwoordig nie, maar dat daar oak 'n beter begrip van die landskap as 'n geheel verskaf word. Die terrein word as 'n kennissentrum beskou, wat sy waarde direk met die konteks in verband bring. Die verspreiding van kennis sal die erfenis toeganklik maak vir nie net wetenskaplikes nie, maar ook vir die gemeenskap. / Mini Dissertation (MArch (Prof))--University of Pretoria, 2016. / Architecture / MArch (Prof) / Unrestricted

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2013. / Recent studies of the dental remains from Malapa, a fossil-bearing karstic cave-site located in the Cradle of Humankind (Berger et al., 2010), have demonstrated the presence of dental calculus and associated plant material in the form of phytoliths, preserved on the teeth of Australopithecus sediba (MH1) (Henry et al., 2012). This discovery raised the probability that dental calculus and plant microremains may also be present on hominin material from other cave sites in southern Africa, where fossils are preserved under similar conditions. The aim of this study was to establish the presence of dental calculus and associated microfossils on the teeth of other southern African Plio-Pleistocene early hominins. The dental collection of the Plio-Pleistocene age hominin site of Sterkfontein was examined. Where fossils were observed with adherent material, several analyses were performed to determine whether this material was calculus or not. Where possible, comparisons with the texture of the sediment matrix surrounding the fossil were conducted. Small quantities of this material were removed and observed microscopically to determine if it included food particulates and microfossils. In these cases, we also looked for microfossils in the surrounding matrix as a control. Phytoliths were recovered from all tooth sample material tested. The establishment of phytoliths in the dental calculus is direct evidence that these two structures existed simultaneously, as the formation of calculus can only take place in the presence of saliva. A large number of phytolith morphotypes further indicated that A.africanus had an adaptable and diverse diet, and that monocotyledons and dicotyledons appear to have made up a considerable part of their diet. The results from this study will benefit future analyses, by not only providing new protocols for establishing the presence of dental calculus, but also for promoting better preservation of dental calculus in the future. Further, future studies may be able to obtain direct evidence of consumed food that can directly be associated with individual hominins’ feeding behaviours. This could result in significant clues to the diet and ecology of not only individual hominins, but populations, species and comparisons of diet and behaviour between species and genera.

The natural vegetation of the Cradle of Humankind World Heritage Site (COH WHS) was classified using Braun-blanquet methodology. This identified 22 distinct plant communities and 2 variants. Sampling took place over two growing seasons with a total of 91 releves being compiled. A stratified random approach to sampling used Land Types as a means of primary area stratification, with terrain position providing the means for further refinement. The grassland comprised of 12 plant communities and 2 variants and the woodland comprised of 10 plant communities. The classification of the woodland areas included some bush clumps associated with the entrances of caves which were also described independently in which seven distinct plant communities were identified A positive linear correlation exists between the size of the cave entrances and the extent to which the surrounding woody vegetation extends. This suggests the likelihood of cave entrance size influencing the surrounding vegetation. / Environmental Sciences / M. Tech. (Nature Conservation)

The natural vegetation of the Cradle of Humankind World Heritage Site (COH WHS) was classified using Braun-blanquet methodology. This identified 22 distinct plant communities and 2 variants. Sampling took place over two growing seasons with a total of 91 releves being compiled. A stratified random approach to sampling used Land Types as a means of primary area stratification, with terrain position providing the means for further refinement. The grassland comprised of 12 plant communities and 2 variants and the woodland comprised of 10 plant communities. The classification of the woodland areas included some bush clumps associated with the entrances of caves which were also described independently in which seven distinct plant communities were identified A positive linear correlation exists between the size of the cave entrances and the extent to which the surrounding woody vegetation extends. This suggests the likelihood of cave entrance size influencing the surrounding vegetation. / Environmental Sciences / M. Tech. (Nature Conservation)

M.Sc. (Geology) / The Cradle of Humankind is a 47 000 hectare demarcated area with over three dozen fossil-bearing cave sites well known for the preservation of fossil evidence of early hominin taxa such as Australopithecus Africanus, Australopithecus Sediba, Paranthropus Robustus and Early Homo. As a result, a database of precise and accurate chronological data for fossil-bearing cave deposits of the Cradle of Humankind (similar to that for East African fossil sites) is very important, but developing one has proven extremely challenging. The main challenge is that the fossil-bearing deposits at the cradle are mainly complex breccias with a chaotic, localized stratigraphy and no association to any volcanic ash beds, unlike the East African deposits which are lacustrine and fluviatile deposits interbedded with volcanic ash layers. However, substantial success has been obtained recently through the combination of U-Pb dating of CaCO₃ speleothems and palaeomagnetic dating (magnetostratigraphy) after many attempts and unconvincing results from techniques such as biostratigraphic correlations, electron spin resonance on teeth and cosmogenic burial dating of the sediments. The problem with U-Pb dating of CaCO₃ speleothems is that this requires samples that are extremely clean (i.e. detrital-free) and have an appreciable U content (close to 1 ppm), and such material is at many sites not available...

This dissertation is a set of three essays connected by the common theme of our epistemic fragility: the way in which our knowledge – of our own minds, of whether we are in violation of the epistemic and ethical norms, and of the philosophical truths themselves – is hostage to forces outside our control. The first essay, “Are We Luminous?”, is a recasting and defence of Timothy Williamson’s argument that there are no non-trivial conditions such that we are in a position to know we are in them whenever we are in them. Crucial to seeing why Williamson’s anti-luminosity argument succeeds, pace various critics, is recognising that the issue is largely an empirical one. It is in part because of the kind of creatures we are – specifically, creatures with coarse-grained doxastic dispositions – that nothing of interest, for us, is luminous. In the second essay, “What’s in a Norm?”, I argue that such an Anti-Cartesian view in turn demands that epistemologists and ethicists accept the ubiquity of normative luck, the phenomenon whereby agents fail to do what they ought because of non-culpable ignorance. Those who find such a view intolerable – many epistemic internalists and ethical subjectivists – have the option of cleaving to the Cartesian orthodoxy by endorsing an anti-realist metanormativity. The third essay, “The Archimedean Urge”, is a critical discussion of genealogical scepticism about philosophical judgment, including evolutionary debunking arguments and experimentally-motivated attacks. Although such genealogical scepticism often purports to stand outside philosophy – in the neutral terrains of science or common sense – it tacitly relies on various first-order epistemic judgments. The upshot is two-fold. First, genealogical scepticism risks self-defeat, impugning commitment to its own premises. Second, philosophers have at their disposal epistemological resources to fend off genealogical scepticism: namely, an epistemology that takes seriously the role that luck plays in the acquisition of philosophical knowledge.

Bayesian epistemology provides a promising framework for a theory of epistemic rationality. But the way in which this framework has been built upon thus far yields an unfortunately mechanical picture of rationality, on which rational agents are mere data crunchers who receive evidential input and spit out numeric credal output. This picture is rightly criticized, most prominently by Bas van Fraassen, for being too narrow and restrictive and thus failing to account for certain features which rationality plausibly has, such as a degree of permissiveness, and for certain unconventional rational phenomena, such as conversions. Unfortunately, van Fraassen’s apt criticism of mechanistic rationality overshoots its mark in seeking to topple the entire Bayesian framework. Bayesian epistemology suffers a guilt by association with the robotic picture. This dissertation aims to restore Bayesianism from the mechanistic but often implicit assumptions which corrode it, and to rebuild, from the Bayesian foundation, an alternative picture of rationality as a property of sentient agents who are capable of understanding and mentally engaging with the objects of their credences. Along the way I account for some basic Bayesian objects such as credence and evidential input. I also accord a central role to the ability of representational experiences, largely sidelined in many Bayesian discussions, to give rise to surprising evidence. On these building blocks I develop theory of rationality, Expansive Bayesianism, which evades the criticisms launched at the robotic picture and shows that Bayesianism itself is a fruitful and powerful framework for a theory of rationality.

This thesis explores two sets of issues in contemporary epistemology. The first part explores issues surrounding the category of basic knowledge (or justification) – that is, at a first-pass, knowledge (or justification) which is immediate, in the sense that one’s justification for the known proposition doesn’t rest on any justification for believing other propositions. The second part investigates issues surrounding knowledge-closure and various conditions – namely, conclusive reasons, sensitivity, and safety – which some philosophers have claimed are necessary for knowledge. Each part of the thesis is substantial (there are five chapters in the first part and four in the second), and the two sets of issues – while evidently of independent interest – are interrelated in several ways. In broad outline, part one of the thesis concludes that, even if (in the worst case) the first-pass category of basic knowledge delineated above is not ultimately tenable (on account of credible arguments against it considered in chapter 5), there is a distinct category of knowledge, aptly called ‘basic’, which is, plausibly, tenable. Part two of the thesis, meanwhile, begins by attempting to render the conclusive reasons and sensitivity conditions – conditions the adoption of which involves rejection of knowledge-closure – in as plausible a form as possible. And a rejection of knowledge-closure has implications for the viability of the first-pass category of basic knowledge delineated above, in particular. Part two closes by exploring the safety condition: a start is made at defending a novel safety condition; and a possible application of the safety condition to the legal domain is considered. The Conclusion, which includes a prospectus for further work, ties the safety condition on knowledge (chapters 8 and 9) back to the notion of failure of transmission of epistemic warrant (an absolutely central notion in part one).

Orientador: Helen Barbosa Raiz Engler / Banca: Wlaumir Doniseti de Souza / Banca: Ubaldo Silveira / Resumo:O presente estudo objetiva suscitar algumas reflexões sobre as condições de vida, de trabalho e as estratégias de sobrevivência das mulheres negras que se encontram na informalidade no município de Franca, com ênfase para o trabalho domiciliar. Partimos de uma análise sobre as profundas alterações ocorridas nas últimas décadas no mundo do trabalho, que modificou as formas de gerir e organizar os processos produtivos em decorrência de novos imperativos da ordem capitalista. Como estratégia de saída das crises, o próprio sistema criou medidas para dar continuidade aos seus ideários, como ocorreu com o processo de reestruturação produtiva. Frente aos novos arranjos do setor produtivo, verificamos o crescimento do desemprego, degradação das condições de trabalho diante do desmonte dos direitos trabalhistas, outrora conquistados, e expansão da informalidade, caracterizada pelo descumprimento da legislação e ausência de proteção social. Nesse horizonte, houve uma intensificação das subcontratações e do trabalho domiciliar, engendrados pela lógica da terceirização. Isso é perceptível no cenário de Franca, município localizado na região nordeste do estado de São Paulo e que tem como pólo econômico a produção do calçado masculino de couro. É nesse locus que se dá a realização da respectiva pesquisa. O trabalho domiciliar, que não corresponde a nenhuma novidade no município de Franca, toma um novo redimensionamento com sua intensificação no contexto da reestruturação produtiva. A indústria calçadista francana passa a adotar a filosofia de redução dos custos da força de trabalho como estratégia para se consolidar no mercado capitalista, redundando em êxitos para o ramo coureiro-calçadista e provocando a transferência de processos produtivos, como a costura manual do calçado, para o ambiente domiciliar, marcado pela precariedade ...(Resumo completo, clicar em acesso eletronico abaixo) / Abstract: The present study objectives to excite some reflections about the conditions of life, work and the strategies of survival of the black women who find in the informality in Franca-SP, with emphasis on the domiciliary work. We started of an analysis on the deep alterations occurred in the last decades in the world of the work, that modified the forms to manage and to organize the productive processes in result of new imperatives of the capitalist order. As strategy of exit of the crises, the system itself created measures to give continuity to its ideas, as it occurred with the process of productive reorganization. In the presence of the new arrangements of the productive sector, we verify the growth of the unemployment, degradation of the work conditions by the dismounting of the labor laws long ago conquered and expansion of the informality, characterized for the non-accomplishment of the legislation and absence of social protection. In this horizon, it had an intensification of the under-agreements and of the domiciliary work, produced for the logic of the outsourcing. This is perceivable in the Franca scene, city located in the northeast region of the state of São Paulo and it has as economic power the production of the leather masculine footwear. The accomplishment of the respective research occurs in this locus. The domiciliary work, which does not correspond to any newness in Franca, takes a new dimension with its intensification in the context of the productive reorganization. The shoe industry of Franca starts to adopt the philosophy of reduction of the costs of the work force as strategy to consolidate itself in the capitalist market, resulting in successes for the leather-shoemarker branch and provoking the transference of productive processes, as the manual sewing of the footwear, to domiciliary surrounding it, marked for the precariousness and invisibly work relationships ...(Complete abstract click electronic access below) / Mestre