RELAÇÃO E EFEITOS BIOQUÍMICO-NUTRICIONAIS SOBRE OS TRANSTORNOS DO CICLO ESTRAL DE VACAS -/- Emanuel Isaque Cordeiro da Silva Departamento de Agropecuária – IFPE Campus Belo Jardim [email protected] ou [email protected] WhatsApp: (82)98143-8399 -/- •__6. Transtornos do ciclo estral -/- Qualquer alteração na frequência, duração ou intensidade do ciclo estral é considerada uma perturbação do ciclo, cujas origens variam etiologicamente. As perturbações do ciclo podem originar-se em qualquer das partes do eixo hipotálamo-hipófise-ovário (FRAZER, 2005; GORDON, 1996). Pode ou não ser do (...) tipo permanente e pode depender de sua origem, momento e intensidade cursar com outras alterações reprodutivas, por exemplo uma retenção do corpo lúteo, dá lugar a prolongamento da fase lútea, altos níveis de progesterona circulante e pode, finalmente, desencadear em um cisto luteal ou em uma metrite. Entre os fatores desencadeadores da falha do ciclo estral estão os fatores de origem nutricional, dentre eles: 6.1 Minerais 6.1.1 Relação Na:K (Sódio: Potássio) A deficiência de sódio pode causar distúrbios do ciclo estral, isto porque as células animais intracelularmente possuem uma alta concentração de K e uma baixa concentração de Na, esta relação pode chegar a 10:1 ou mais, em relação ao meio externo. Com esta relação, as concentrações intracelulares estão em equilíbrio com o meio externo. A absorção e secreção de cátions pela célula para conseguir o equilíbrio é simultânea, gerada por um sistema de transporte específico chamado "bomba Na-K". Se a nível celular não existe um balanço iônico de K:Na, a maior prioridade das células tubulares do rim é a de conseguir novamente um equilíbrio, o mecanismo destas células é o da reabsorção do íon que se encontre em excesso de água, diminuindo a quantidade deste no líquido para manter as funções em equilíbrio dinâmico. Os desequilíbrios não compensados a nível celular ou renal, levam a alterações na condutividade nervosa por alteração da bomba de transmissão elétrica. O ciclo estral é alterado por diminuir a expressividade dos sinais comportamentais de estro, que são produzidos por concentrações crescentes de estrogênio mas com alta necessidade de adequação nervosa para a exposição corporal do cio e a aceitação da monta. O potássio, em particular, desempenha um papel fundamental como coator em certas interações enzimáticas, incluindo a transferência de energia, a síntese de proteínas e o metabolismo de hidratos de carbono, em especial nos sistemas em que o ADP está envolvido, as hexoquinases e a anidrase carbônica. O sódio, por sua vez, é o principal cátion extracelular, regula o equilíbrio hídrico no organismo e a mecânica de fluidos, desta forma regula a pressão osmótica e a troca aquosa nos tecidos. Devido a esta função, um dos fatores importantes do fluxo Na:K é o rim, que é controlado pela aldosterona, a principal hormona reguladora da absorção de sódio e excreção de potássio. Qualquer desequilíbrio na relação Na:K, afetará o ciclo estral, de maneira direta e indireta, através da alteração na síntese de proteínas e da perda da regulação hídrica, fator importante pelas secreções que devem acompanhar as manifestações de cio/estro. 6.1.2 Relação Cobalto (Co) A deficiência de cobalto gera um efeito biológico determinado pela sua presença na molécula da vitamina B12, a qual regula a hematopoese (Ativa a síntese de protoporfirina) e afeta o metabolismo do nitrogênio e dos carboidratos. A vitamina B12 atua como uma coenzima da transmetilação (síntese do glutamato mutase, metilmalonil-CoA-Mutase, diol-dehidratase e redução dos ribonucleótidos a desoxirribonucleótidos, isomerização da a-lisina, etc.). Especialmente em ruminantes, a reação mutase da metilmalonina-CoA está relacionada com o metabolismo do ácido propiônico e, portanto, com a síntese de glicose e o equilíbrio energético. O cobalto também está envolvido na carboxilação da propionil-CoA à metilmalonil-CoA e na isomerização deste último para succinil-CoA. O metabolismo do ácido propiônico ocorre no fígado e é reduzido pelo fato do metilmalonil não poder ser convertido em succinil-CoA, impedindo a sua passagem para oxalacetato e glicose, gerando uma relação inversa entre os níveis de energia e proteína; causando uma diminuição de GnRH que afeta negativamente a liberação de LH que, por sua vez, cria um aumento na FSH. Isso produz uma anulação da ovulação e, consequentemente, ausência de um ciclo estral verdadeiro. Vale reforçar que, para prevenção da deficiência do cobalto, o criador pode optar pelo fornecimento de volumosos que dispõem de quantidades de cobalto que suprem as exigências dos animais, ou pela inserção de sais de cobalto à mistura da ração, sempre no intervalo sugerido de 0,07 e 0,11 mg/kg para cada animal, suprindo a necessidade do mesmo e garantindo assim a prevenção dos transtornos do ciclo estral ou outras afecções do sistema reprodutivo. 6.1.3 Relação Cobre (Cu) e Molibdênio (Mo) A deficiência de cobre gera, indiretamente, molibdênio, durante esse processo, tanto o macho como a fêmea são inférteis ou sub-férteis, mas, em geral, os transtornos surgem não por molibdeniose mas por hipocuprose condicionada por excesso de molibdênio nas pastagens e pelos sulfatos presentes na água de bebida (BREM, 2016). Isso leva à formação de tiomolibdato no rúmen, que por sua vez combina com o cobre para formar tiomolibdato de cobre, sal muito insolúvel. O tiomolibdato presente, formado em excesso e que não encontra cobre suficiente, contribuirá para produzir a diarreia, limitando ainda mais a absorção de cobre. A interferência mais importante do molibdênio ocorre no processo metabólico do cobre, interferindo sua atividade enzimática. O molibdênio atua sobre o complexo sulfeto-oxidase hepático. A enzima que está envolvida na oxidação de metabolitos sulfurados, reduz a sua atividade na presença de altos teores de molibdênio, especialmente quando a quantidade de cobre é baixa. Daqui resulta a formação de sulfureto de cobre, muito insolúvel e, portanto, pouco ou nada utilizável pelas células e/ou tecidos (QUIROZ-ROCHA & BOUDA, 2001). O excesso de molibdênio nas pastagens ou na água de bebida reduz a quantidade de cobre no fígado, mas para uma dada dose de molibdênio, esta redução é diretamente proporcional ao aumento dos sulfatos na ingestão, porque só na presença de sulfatos o molibdênio exerce sua ação limitante. O melhor modo de tratar o molibdênio e a ação dos sulfatos sobre o cobre, é aumentar a quantidade de cobre disponível pelos animais, seja por via bucal ou parenteral. Desta forma, há aumentos na cupremia e no ganho de peso. É conveniente, para o efeito, efetuar um controle dos resultados mediante a observação clínica, pesagem dos animais e análise de cobre no sangue. Isso permitirá estabelecer as doses ideais e adequadas para cada estabelecimento e efetuar um estudo econômico da suplementação (BAVERA, 2002). Como já foi tratado o requerimento do cobre para evitar os problemas reprodutivos das vacas, falemos do molibdênio (Mo). O Mo é um elemento primordial para bovinos leiteiros, uma vez que é componente de uma enzima presente no leite (xantina oxidasse). A deficiência de Mo a nível prático não foi relatada, porém casos podem acontecer. Para ovinos, que é uma espécie ruminante, a concentração exigida pelo animal em Mo presente na MS é de 5 a 10 mg/kg, porém deve levar em consideração a relação crítica entre o Mo e o Cu que deve ser no máximo 20 e nunca superior. O nível crítico de toxidade de Mo nos alimentos volumosos (forrageiras, gramíneas e leguminosas) não pode ultrapassar os 6% por kg de MS. Através de todos esses cuidados, o criador poderá obter sucesso tanto na prevenção contra os distúrbios do ciclo estral das vacas, quanto de outras complicações como toxidade, desnutrição, etc. 6.2 Relação energia:proteína Em relação ao aumento do consumo de proteína crua ou de deficiência de energia, aumenta-se a quantidade de ureia no sangue e produz-se uma toxicidade tecidular, afetando o endométrio e diminuindo a produção de prostaglandinas, que são as encarregadas de manter o corpo lúteo, caso não se mantenha acaba provocando um ciclo estral longo. A situação pode ser explicada a nível do eixo hipotálamo-hipófise, no qual os baixos níveis de glicose inibem a secreção de GnRH e resultam na diminuição da pulsatilidade da LH, seja por ação direta ou mediada através das ß-endorfinas. Outro fator que afeta o crescimento folicular é a nutrição, especificamente a perda da condição corporal, quando o animal não se alimenta direito ou quando se alimenta não tem uma condição balanceada que supra suas exigências nutricionais e que tenha um aceitável ganho de peso diário (GPD), acaba perdendo massa muscular ou de gordura, em outras palavras altera-se a condição corporal do mesmo, e se a perda for de 22 a 24 % de peso corporal (PC), os animais que perdem essa condição entram em anestro o que acaba tornando um animal inviável para a reprodução e também para o abate, uma vez que encontra-se fora do peso ideal. Tanto as proteínas quanto a energia foram tratados em trabalhos anteriores, porém nunca é tarde para salientar que ambas devem ser fornecidas em qualidade e quantidade que consiga favorecer ao desenvolvimento do animal e aos mecanismos fisiológicos do mesmo. 6.3 Fito-toxidade Finalmente, um fator adicional que induz a alteração da ciclicidade estral são os fitoestrógenos, plantas com altos teores de isoflavonas que possuem, no organismo animal, uma ação estrogênica. Os fitoestrógenos estão amplamente difundidos, nos trevos, alfafa, milho e nas pastagens de cultivo intensivo. Os fitoestrogênios são diferentes dos estrogênios produzidos pelo animal, mas a sua ação é idêntica nos receptores do trato reprodutivo; o seu metabolismo e excreção é diferente (por exemplo, desmetilização) e a sua excreção renal através dos glicoronosidos, assim mesmo a formação de ésteres sulfatos no tecido hepático é menor, acumulando-se em circulação e alterando a duração da fase estrogênica do ciclo, isso leva à ninfomania das vacas e com ela a perda da função reprodutiva. Deve-se estar atento ao pasto que se cultiva e ao solo em que se implanta o pasto, uma vez que o solo pode ter excessos de minerais prejudiciais ao animal e que o coloque em uma situação de toxidade, já que a planta absorve do solo o excesso e da planta vai para o animal por meio direto ou pela silagem. Um exemplo é o teor de molibdênio na planta que não pode ser maior que 6%, se for ocorrerá inúmeras transformações fisiológicas maléficas ao animal, que acabará sendo descartado do objetivo que seria a reprodução na fazenda. -/- Apoio -/- Realização -/- REFERÊNCIAS BIBLIOGRÁFICAS BAVERA, Guillermo Alejandro. Aguas y aguadas para el ganado. Rio Cuarto: Inter-Medica Editorial, 2009. BERCHIELLI, Telma Teresinha; PIRES, Alexandre Vaz; OLIVEIRA, SG de. Nutrição de ruminantes. Jaboticabal: funep, 2006. BINDARI, Yugal Raj et al. Effects of nutrition on reproduction-A review. Adv. Appl. Sci. Res, v. 4, n. 1, p. 421-429, 2013. BOLAND, M. P. Efectos nutricionales en la reproducción del ganado. XXXI Jornadas Uruguayas de Buiatría, 2003. BREM, J. J. et al. Alteraciones del ciclo estral provocadas por un alto ingreso de molibdeno en vaquillonas Brangus y respuesta a la suplementación con cobre. Revista Veterinaria, v. 12, n. 1 y 2, p. 28-33, 2016. DEHNING, R. Interrelaciones entre nutrición y fertilidad. In: Curso Manejo de la Fertilidad Bovina18-23 May 1987Medellín (Colombia). CICADEP, Bogotá (Colombia) Universidad de La Salle, Medellín (Colombia) Instituto Colombiano Agropecurio, Bogotá (Colombia) Sociedad Alemana de Cooperación Técnica-GTZ (Alemania), 1987. DE LUCA, Leonardo J. Nutrición y fertilidad en el ganado lechero. XXXVI Jornadas Uruguayas de Buiatría, 2008. FRAZER, Grant S. Bovine theriogenology. Veterinary Clinics: Food Animal Practice, v. 21, n. 2, p. xiii-xiv, 2005. GORDON, Ian. Controlled reproduction in farm animals series. Nova Iorque: CAB International, 1996. GRAHAM, Thomas W. Trace element deficiencies in cattle. Veterinary clinics of North America: food animal practice, v. 7, n. 1, p. 153-215, 1991. GUEDES, Luciana Freitas et al. A importância do cobre, molibdênio e enxofre na alimentação de ovinos. Nucleus Animalium, v. 10, n. 2, p. 7-22, 2018. HURLEY, W. L.; DOANE, R. M. Recent developments in the roles of vitamins and minerals in reproduction. Journal of Dairy Science, v. 72, n. 3, p. 784-804, 1989. KUMAR, Sudhir et al. Importance of micro minerals in reproductive performance of livestock. Veterinary world, v. 4, n. 5, p. 230, 2011. MAAS, John. Relationship between nutrition and reproduction in beef cattle. The Veterinary Clinics of North America. Food Animal Practice, v. 3, n. 3, p. 633-646, 1987. MILLS, C. F. Cobalt deficiency and cobalt requirements of ruminants. Recent advances in animal nutrition, p. 129-141, 1981. NICODEMO, M. L. F.; SERENO, J. R. B.; AMARAL, T. B. Minerais na eficiência reprodutiva de bovinos. Embrapa Pecuária Sudeste-Documentos (INFOTECA-E), São Carlos, 2008. PASA, Camila. Relação reprodução animal e os minerais. Biodiversidade, v. 9, n. 1, 2011. QUIROZ-ROCHA, Gerardo F.; BOUDA, Jan. Fisiopatología de las deficiencias de cobre en rumiantes y su diagnóstico. Vet. Méx, v. 32, n. 4, p. 289, 2001. SHORT, Robert E.; ADAMS, D. C. Nutritional and hormonal interrelationships in beef cattle reproduction. Canadian Journal of Animal Science, v. 68, n. 1, p. 29-39, 1988. YASOTHAI, R. Importance of minerals on reproduction in dairy cattle. International Journal of Science, Environment and Technology, v. 3, n. 6, p. 2051-2057, 2014. Emanuel Isaque Cordeiro da Silva Belo Jardim, 29 de março de 2020. (shrink)

In this paper we show how a realistic normative democratic theory can work within the constraints set by the most pessimistic empirical results about voting behaviour and elite capture of the policy process. After setting out the empirical evidence and discussing some extant responses by political theorists, we argue that the evidence produces a two-pronged challenge for democracy: an epistemic challenge concerning the quality and focus of decision-making and an oligarchic challenge concerning power concentration. To address the challenges we then (...) put forward three main normative claims, each of which is compatible with the evidence. We start with a critique of the epistocratic position commonly thought to be supported by the evidence. We then introduce a qualified critique of referenda and other forms of plebiscite, and an outline of a tribune-based system of popular control over oligarchic influence on the policy process. Our discussion points towards a renewal of democracy in a plebeian but not plebiscitarian direction: Attention to the relative power of social classes matters more than formal dispersal of power through voting. We close with some methodological reflections about the compatibility between our normative claims and the realist program in political philosophy. (shrink)

The paper by Monteiro, Musten and Compson (2014) is to be commended for providing a comprehensive discussion of the compatibility issues arising from the integration of mindfulness – a 2,500-year-old Buddhist practice – into research and applied psychological domains. Consistent with the observations of various others (e.g., Dunne, 2011; Kang & Whittingham, 2010), Monteiro and colleagues have not only highlighted that there are differences in how Buddhism and contemporary mindfulness interventional approaches interpret and contextualize mindfulness, but there are also differing (...) interpretations of mindfulness within Buddhism. These apparent differences within Buddhism are arguably more noticeable when making comparisons across Buddhist vehicles (i.e., Theravada, Mahayana, Vajrayana), but to a lesser extent intra-vehicular differences can also be said to exist (i.e., differences between Buddhist traditions of the same vehicle). This commentary investigates the validity of some of these different Buddhist constructions of mindfulness, and then discusses how a better understanding of their scriptural and conceptual soundness (or lack thereof) may help to reconcile some of the actual and perceived incompatibility between Buddhist practice and contemporary secular mindfulness-based approaches. (shrink)

A discussion of the sense in which reality is mind-dependent for Kant and for David Lewis. Plus a lot about space-aliens (and a bit about pimple-worms).

Objectives. The purpose of this study was to conduct the first randomized controlled trial (RCT) to evaluate the effectiveness of a second-generation mindfulness-based intervention (SG-MBI) for treating fibromyalgia syndrome (FMS). Compared to first generation mindfulness-based interventions, SG-MBIs are more acknowledging of the spiritual aspect of mindfulness. Design. A RCT employing intent-to-treat analysis. Methods. Adults with FMS received an 8-week SG-MBI known as meditation awareness training (MAT; n = 74) or an active control intervention known as cognitive behaviour theory for groups (...) (n = 74). Assessments were performed at pre-, post-, and 6-month follow-up phases. Results. Meditation awareness training participants demonstrated significant and sustained improvements over control group participants in FMS symptomatology, pain perception, sleep quality, psychological distress, non-attachment (to self, symptoms, and environment), and civic engagement. A mediation analysis found that (1) civic engagement partially mediated treatment effects for all outcome variables, (2) non-attachment partially mediated treatment effects for psychological distress and sleep quality, and (3) non-attachment almost fully mediated treatment effects for FMS symptomatology and pain perception. Average daily time spent in meditation was found to be a significant predictor of changes in all outcome variables. Conclusions. Meditation awareness training may be a suitable treatment for adults with FMS and appears to ameliorate FMS symptomatology and pain perception by reducing attachment to self. (shrink)

The norm of assertion, to be in force, is a social norm. What is the content of our social norm of assertion? Various linguistic arguments purport to show that to assert is to represent oneself as knowing. But to represent oneself as knowing does not entail that assertion is governed by a knowledge norm. At best these linguistic arguments provide indirect support for a knowledge norm. Furthermore, there are alternative, non-normative explanations for the linguistic data (as in recent work from (...) Van Elswyk). Direct arguments would rely on normative judgments about the permissibility or impermissibility of assertions with and without the speaker knowing the content asserted. John Turri's work experimental results purport to show that our norm of assertion is factive, and probably knowledge. But as a number of recent experimentalists (Kneer, Reuter and Broessel, Marsili and Wiegmann) have shown, Turri's results rely on the problemmatic use of 'should' as in 'Maria should assert that she owns a 1990 watch.' Correcting for this, these experimentalists provide strong evidence that our norm of assertion is not factive. The standard reply to evidence like this from the assertion of unlucky falsehoods is the excuse maneuver. But Marsili and Wiegmann, following Turri's protocol for testing for excuse validation, show that participants who judge that assertions unlucky falsehoods are permissible are not guilty of excuse validation. Given our current understanding of the experimental evidence, knowledge is not our norm of assertion. (shrink)

Sometimes one can prevent harm only by contravening rights. If the harm one can prevent is great enough, compared to the stringency of the opposing rights, then one has a lesser-evil justification to contravene the rights. Non-consequentialist orthodoxy holds that, most of the time, lesser-evil justifications add to agents’ permissible options without taking any away. Helen Frowe rejects this view. She claims that, almost always, agents must act on their lesser-evil justifications. Our primary task is to refute Frowe’s flagship argument. (...) Secondarily, it is to sketch a positive case for nonconsequentialist orthodoxy. (shrink)

A piece of folklore enjoys some currency among philosophical Bayesians, according to which Bayesian agents that, intuitively speaking, spread their credence over the entire space of available hypotheses are certain to converge to the truth. The goals of the present discussion are to show that kernel of truth in this folklore is in some ways fairly small and to argue that Bayesian convergence-to-the-truth results are a liability for Bayesianism as an account of rationality, since they render a certain sort of (...) arrogance rationally mandatory. (shrink)

This paper discusses the teaching of -- and opposition to the teaching of -- evolutionary theory in Australian schools in the early twenty-first century.

This article is a response to Martin Orensanz’s argument that object-oriented ontology ought to accept the existence of matter as both a sensual and a real object. That matter can exist as a sensual object is a point immediately granted, since “sensual object” is such a broad term that nothing could be excluded from this designation. Yet I argue that this is not the case with respect to real objects, which must exist independently of any other entity that might encounter (...) them. This leads to a related debate on whether parthood is transitive, in which Orensanz takes up a recent argument of Daniel Korman while I defend the modified Aristotelian position that only the proximate parts of an object can be said to belong to it in the strict sense. (shrink)

In this paper, I examine Kant’s discussion of ‘the cosmological argument’ in The Critique of Pure Reason, Transcendental Doctrine of Elements, Second Part, Second Division, Book 2, Chapter Three, Section Five (‘The Impossibility of a Cosmological Proof of the Existence of God’). While there are other places where Kant provides related discussions of ‘the cosmological argument’—e.g. in The Only Possible Argument in Support of a Demonstration of the Existence of God, Lectures on Philosophical Theology, and Religion within the Limits of (...) Reason Alone—I do not attempt to consider any of these further works in this paper. First, I argue that it is not true that cosmological arguments depend upon ontological arguments, and that Kant is simply mistaken when he argues that ‘the cosmological argument’ ‘assumes’ ‘the ontological argument’. Second, I argue that Kant does not provide a compelling critique of cosmological arguments to the conclusion that there is an absolutely necessary being. (shrink)

I examine issues in the philosophy of religion at the intersection of what possibilities there are and what a God, as classically conceived in the theistic philosophical tradition, would be able to do. The discussion is centered around arguing for an incompatibility between theism and two principles about possibility and ability, and exploring what theists should say about these incompatibilities. -/- I argue that theism entails that certain kinds and amounts of evil are impossible. This puts theism in conflict with (...) popular principles of modal recombination. However, theists have plausible explanations for the violations of recombination that they posit, and can suitably amend these principles without giving up their usefulness in accounting for what possibilities there are. -/- I also argue that despite the impossibility of these evils, God is able to bring these evils about. This puts theism in conflict with the principle that no one is able to do the impossible. However, theists can give a plausible account of why God is unique in being able to do the impossible, and have distinctive resources to address the arguments in favor of the idea that no one is able to do the impossible. And by denying this principle, theists are able to resolve several otherwise difficult puzzles, including reconciling conflicts between the divine attributes. (shrink)

We review the "Entitlement" projects of Tyler Burge and Crispin Wright in light of recent work from and surrounding both philosophers. Our review dispels three misunderstandings. First, Burge and Wright are not involved in a common “entitlement” project. Second, though for both Wright and Burge entitlement is the new notion, “entitlement” is not some altogether third topic not clearly connected to the nature of knowledge or the encounter with skepticism. Third, entitlement vs. justification does not align with the externalism vs. (...) internalism distinction. (shrink)

Feser (2017) presents and defends five proofs of the existence of God. Each proof is in two stages: the first stage proves the existence of something which, in the second stage, is shown to possess an appropriate range of divine attributes. Each proof is given two presentations, one informal and one formal. In this paper, I critically examine two premises from one of Feser's five first stage proofs. I provide reasons for thinking that naturalists reject both of these premises. In (...) my view, this enough to show that the proof fails: it fails to advance considerations that decide between theism and important competing positions. (shrink)

In order to give a proper estimation of the place of the New Atheism in history, we shall need to have before us an overview of that history. So I shall begin with an appropriate sketch. Then I will try to give an account of the current global state of play, and to indicate some reasons why it seems reasonable to think that the worldview of the New Atheists is currently gaining ground, at least in certain quarters. After examining—and rejecting—some (...) recent claims that the worldview of the New Atheists is actually now in decline, I will then conclude with some cautionary remarks about the difficulties of making longer term predictions about anything involving human affairs. (shrink)

Proper functionalism explicates epistemic warrant in terms of the function and normal functioning of the belief-forming process. There are two standard substantive views of the sources of functions in the literature in epistemology: God (intelligent design) or Mother Nature (evolution by natural selection). Both appear to confront the Swampman objection: couldn’t there be a mind with warranted beliefs neither designed by God nor the product of evolution by natural selection? Is there another substantive view that avoids the Swampman objection? There (...) are two. The first is the generalized selected-effects theory of functions. The second is the organizational theory of functions. Both, however, require some history to assign functions, for both are etiological theories of functions: past effects help explain current function. Swampman can then acquire functions, perhaps soon after creation, though he has none at the moment of inception. (shrink)

I argue for the viability of one neglected way of developing supervenience-based objections to metaethical non-naturalism. This way goes through a principle known as ‘Hume’s Dictum’, according to which there are no necessary connections between distinct existences. I challenge several objections to the Hume’s Dictum-based argument. In the course of doing so, I formulate and motivate modest and precise versions of Hume’s Dictum, illustrate how arguments employing these principles might proceed, and argue that the Hume’s Dictum argument enjoys some advantages (...) relative to other supervenience-based objections to non-naturalism. (shrink)

This essay revisits some classic problems in the philosophy of space and time concerning the counting of possibilities. I argue that we should think that two Newtonian worlds can differ only as to when or where things happen and that general relativistic worlds can differ in something like the same way—the first of these theses being quaintly heterodox, the second baldly heretical, according to the mores of contemporary philosophy of physics.

Recent discussions of cognitive enhancement often note that drugs and technologies that improve cognitive performance may do so at the risk of “cheapening” our resulting cognitive achievements Arguing about bioethics, Routledge, London, 2012; Harris in Bioethics 25:102–111, 2011). While there are several possible responses to this worry, we will highlight what we take to be one of the most promising—one which draws on a recent strand of thinking in social and virtue epistemology to construct an integrationist defence of cognitive enhancement.. (...) According to such a line, there is—despite initial appearances to the contrary—no genuine tension between using enhancements to attain our goals and achieving these goals in a valuable way provided the relevant enhancement is appropriately integrated into the agent’s cognitive architecture. In this paper, however, we show that the kind of integration recommended by such views will likely come at a high cost. More specifically, we highlight a dilemma for users of pharmacological cognitive enhancement: they can meet the conditions for cognitive integration at the significant risk of dangerous dependency, or remain free of such dependency while foregoing integration and the valuable achievements that such integration enables. After motivating and clarifying the import of this dilemma, we offer recommendations for how future cognitive enhancement research may offer potential routes for navigating past it. (shrink)

The twin goals of this essay are: to investigate a family of cases in which the goal of guaranteed convergence to the truth is beyond our reach; and to argue that each of three strands prominent in contemporary epistemological thought has undesirable consequences when confronted with the existence of such problems. Approaches that follow Reichenbach in taking guaranteed convergence to the truth to be the characteristic virtue of good methods face a vicious closure problem. Approaches on which there is a (...) unique rational doxastic response to any given body of evidence can avoid incoherence only by rendering epistemology a curiously limited enterprise. Bayesian approaches rule out humility about one’s prospects of success in certain situations in which failure is typical. (shrink)

Under so-called primitive ontology approaches, in fully describing the history of a quantum system, one thereby attributes interesting properties to regions of spacetime. Primitive ontology approaches, which include some varieties of Bohmian mechanics and spontaneous collapse theories, are interesting in part because they hold out the hope that it should not be too difficult to make a connection between models of quantum mechanics and descriptions of histories of ordinary macroscopic bodies. But such approaches are dualistic, positing a quantum state as (...) well as ordinary material degrees of freedom. This paper lays out and compares some options that primitive ontologists have for making sense of the quantum state. (shrink)

If you want to understand McDowell's spatial metaphors when he talks about perceptual knowledge, place him side-by-side with Dretske on perceptual knowledge. Though McDowell shows no evidence of reading Dretske's writings on knowledge from the late 1960s onwards (McDowell mentions "Epistemic Operators" once in passing), McDowell gives the same four arguments as Dretske for the conclusion that knowledge requires "conclusive" reasons that rule of the possibility of mistake. Despite various differences, we think it is best to read McDowell as re-discovering (...) Dretske on perceptual knowledge. Since Dretske is easy to understand, all of McDowell's metaphors become easy to understand. But what about McDowell's disjunctivism? Turns out McDowell is not an ontological disjunctivist, and his epistemological disjunctivism is really just the banal point that some perceptual experiences provide conclusive reasons for perceptual belief and some do not. Perceptual experiences are either conclusive or inconclusive. Dretske would agree. (shrink)

I endorse the following claims in this paper. (1) Agnosticism is suspension of judgment on existence claims concerning gods and God. (2) Historical agnostics accepted (1) but unwisely insisted on further conditions best set aside. (3) Particular case agnosticism is less problematic than general principle-based agnosticism. (4) Agnostics should suspend judgment on—or, on occasion, reject—atomic claims of the form ‘God is F’.

How should we undertand the role of norms—especially epistemic norms—governing assertive speech acts? Mitchell Green (2009) has argued that these norms play the role of handicaps in the technical sense from the animal signals literature. As handicaps, they then play a large role in explaining the reliability—and so the stability (the continued prevalence)—of assertive speech acts. But though norms of assertion conceived of as social norms do indeed play this stabilizing role, these norms are best understood as deterrents and not (...) as handicaps. This paper explains the stability problem for the maintenance of animal signals, and so human communication, for we are animals too, after all; the mechanics of the handicap principle; the role of deterrents and punishments as an alternative mechanism; and the role of social norms governing assertion for the case of human communication. (shrink)

There are many parts of science in which a certain sort of underdetermination of theory by evidence is known to be common. It is argued that reflection on this fact should serve to shift the burden of proof from scientific anti-realists to scientific realists at a crucial point in the debate between them.

There seems to be a widespread conviction — evidenced, for example, in the work of Mackie, Dawkins and Sober — that it is Darwinian rather than Humean considerations which deal the fatal logical blow to arguments for intelligent design. I argue that this conviction cannot be well-founded. If there are current logically decisive objections to design arguments, they must be Humean — for Darwinian considerations count not at all against design arguments based upon apparent cosmological fine-tuning. I argue, further, that (...) there are good Humean reasons for atheists and agnostics to resist the suggestion that apparent design — apparent biological design and/or apparent cosmological fine-tuning — establishes (or even strongly supports) the hypothesis of intelligent design. (shrink)

Robert Audi’s Seeing, Knowing, and Doing argues that knowledge does not entail justification, given a broadly externalist conception of knowledge and an access internalist conception of justification, where justification requires the ability to cite one’s grounds or reasons. On this view, animals and small children can have knowledge while lacking justification. About cases like these and others, Audi concludes that knowledge does not entail justification. But the access internalist sense of “justification” is but one of at least two ordinary senses (...) of the term. On a broader or looser sense, “justification” means “being in the right” where that involves meeting a standard or norm. I argue that the beliefs of animals and small children can then meet standards or norms associated with truth and knowledge such that their beliefs may count as justified in this broader or looser sense. I then question whether knowledge fails to entail justification on this broader sense. (shrink)

It is widely thought that chance should be understood in reductionist terms: claims about chance should be understood as claims that certain patterns of events are instantiated. There are many possible reductionist theories of chance, differing as to which possible pattern of events they take to be chance-making. It is also widely taken to be a norm of rationality that credence should defer to chance: special cases aside, rationality requires that one’s credence function, when conditionalized on the chance-making facts, should (...) coincide with the objective chance function. It is a shortcoming of a theory of chance if it implies that this norm of rationality is unsatisfiable. The primary goal of this paper is to show, on the basis of considerations concerning computability and inductive learning, that this shortcoming is more common than one would have hoped. (shrink)

This paper is concerned with learners who aim to learn patterns in infinite binary sequences: shown longer and longer initial segments of a binary sequence, they either attempt to predict whether the next bit will be a 0 or will be a 1 or they issue forecast probabilities for these events. Several variants of this problem are considered. In each case, a no-free-lunch result of the following form is established: the problem of learning is a formidably difficult one, in that (...) no matter what method is pursued, failure is incomparably more common that success; and difficult choices must be faced in choosing a method of learning, since no approach dominates all others in its range of success. In the simplest case, the comparison of the set of situations in which a method fails and the set of situations in which it succeeds is a matter of cardinality (countable vs. uncountable); in other cases, it is a topological matter (meagre vs. co-meagre) or a hybrid computational-topological matter (effectively meagre vs. effectively co-meagre). (shrink)

This paper is concerned with the relation between two notions: that of two solutions or models of a theory being related by a symmetry of the theory and that of solutions or models being physically equivalent. A number of authors have recently discussed this relation, some taking an optimistic view, on which there is a suitable concept of the symmetry of a theory relative to which these two notions coincide, others taking a pessimistic view, on which there is no such (...) concept. The present paper arrives at a cautiously pessimistic conclusion. (shrink)

Jennifer Lackey ('Testimonial Knowledge and Transmission' The Philosophical Quarterly 1999) and Peter Graham ('Conveying Information, Synthese 2000, 'Transferring Knowledge' Nous 2000) offered counterexamples to show that a hearer can acquire knowledge that P from a speaker who asserts that P, but the speaker does not know that P. These examples suggest testimony can generate knowledge. The showpiece of Lackey's examples is the Schoolteacher case. This paper shows that Lackey's case does not undermine the orthodox view that testimony cannot generate (...) knowledge. This paper explains why Lackey's arguments to the contrary are ineffective for they misunderstand the intuitive rationale for the view that testimony cannot generate knowledge. This paper then elaborates on a version of the case from Graham's paper 'Conveying Information' (the Fossil case) that effectively shows that testimony can generate knowledge. This paper then provides a deeper informative explanation for how it is that testimony transfers knowledge, and why there should be cases where testimony generates knowledge. (shrink)

Hylomorphism is the Aristotelian theory according to which substances are composites of matter and form. If my house is a substance, then its matter would be a collection of bricks and timbers and its form something like a structure that unites those bricks and timbers into a single substance. Contemporary hylomorphists are divided on how to understand forms best, but a prominent group of theorists argue that forms are emergent powers. According to such views, when material components are arranged appropriately, (...) a novel substance emerges with the power to impose unity on its components through time. I argue that these accounts of form fall prey to a bootstrapping problem, and so, suffer from issues of redundancy, given plausible assumptions about inherence. In their place, I suggest an ontologically minimalist conception of forms as collective manifestations of the powers of matter. (shrink)

Epistemic defeat is standardly understood in either evidentialist or responsibilist terms. The seminal treatment of defeat is an evidentialist one, due to John Pollock, who famously distinguishes between undercutting and rebutting defeaters. More recently, an orthogonal distinction due to Jennifer Lackey has become widely endorsed, between so-called doxastic (or psychological) and normative defeaters. We think that neither doxastic nor normative defeaters, as Lackey understands them, exist. Both of Lackey’s categories of defeat derive from implausible assumptions about epistemic responsibility. Although Pollock’s (...) evidentialist view is superior, the evidentialism per se can be purged from it, leaving a general structure of defeat that can be incorporated in a reliabilist theory that is neither evidentialist nor responsibilist in any way. (shrink)

Intuitively, a classical field theory is background-in- dependent if the structure required to make sense of its equations is itself subject to dynamical evolution, rather than being imposed ab initio. The aim of this paper is to provide an explication of this intuitive notion. Background-independence is not a not formal property of theories: the question whether a theory is background-independent depends upon how the theory is interpreted. Under the approach proposed here, a theory is fully background-independent relative to an interpretation (...) if each physical possibility corresponds to a distinct spacetime geometry; and it falls short of full background-independence to the extent that this condition fails. (shrink)

Like Lewis, many philosophers hold reductionist accounts of chance (on which claims about chance are to be understood as claims that certain patterns of events are instantiated) and maintain that rationality requires that credence should defer to chance (in the sense that under certain circumstances one's credence in an event must coincide with the chance of that event). It is a shortcoming of an account of chance if it implies that this norm of rationality is unsatisfiable by computable agents. This (...) shortcoming is more common than one might have hoped. (shrink)

Robert Koons claims that my previous critique of his “new” cosmological argument is vitiated by confusion about the nature of defeasible argumentation.In response, I claim that Koons misrepresents—and perhaps misunderstands—the nature of my objections to his “new” cosmological argument. The main claims which I defend are: (1) that the move from a non-defeasible to a defeasible causal principle makes absolutely no difference to the success of the cosmological argument in which it is contained; and (2) that, since it is perfectly (...) well understood that non-theists have many reasons for rejecting the defeasible causal principle, it is pointless to claim that the move to a defeasible principle brings about a shift in the “burden of proof”. (Since some people may have forgotten—or may choose to ignore—the fact that non-theists do have reasons for rejecting the defeasible causal principle, I also provide a discussion of a modest sample of these reasons.). (shrink)

Hylomorphism is the Aristotelian theory according to which objects are composites of form and matter. Form is what unifies the various parts of an object – the matter – into a cohesive whole. Some contemporary hylomorphists argue their theory applies beyond the realm of concreta, and that it explains the unity of various abstract entities. Not everyone agrees. Recent criticism alleges that hylomorphism fails to explain the unity of certain abstract entities, namely, complex properties – properties with other properties as (...) proper parts. Here, I both respond to this criticism and show that and how hylomorphism extends to the domain of complex properties. By discussing hylomorphism’s applicability to the hitherto unchartered domain of complex properties, I hope to defend its credentials as a general mereological theory. (shrink)

The prelims comprise: Introduction: Two Semantic Projects History The Uses of Semantics Conclusions.

A proper function of an entity is a beneficial effect that helps explain the persistence of the entity. Proper functions thereby arise through feedback mechanisms with beneficial effects as inputs and persistence as outputs. We continue to make assertions because they benefit speakers by benefiting speakers. Hearers benefit from true information. Speakers benefit by influencing hearer belief. If hearers do not benefit, they will not form beliefs in response to assertions. Speakers can then only maintain influence by providing true information, (...) often enough. The function of assertion is then inducing true hearer belief. When interests conflict, however, some mechanism must ensure that speakers provide true information often enough, instead of deceiving, or providing information regardless of quality. In humans, a core mechanism stabilizing true assertion involves social norms for truth telling. We tell the truth partly because we prescribe and enforce telling the truth. (shrink)

This paper is a history of philosophy in Australia in the first decade of the twenty-first century. It considers, among other things: (1) the state of the higher education sector; (2) the state of the humanities; (3) the state of philosophy in the academy; (4) support for philosophy in the academy; (5) the role of philosophy beyond the academy; (6) changes in philosophical practice in this decade,; (7) changes in the teaching of philosophy in this decade; and (8) the domains (...) of inquiry in which philosophers worked in this decade. (shrink)

This paper argues for the general proper functionalist view that epistemic warrant consists in the normal functioning of the belief-forming process when the process has forming true beliefs reliably as an etiological function. Such a process is reliable in normal conditions when functioning normally. This paper applies this view to so-called testimony-based beliefs. It argues that when a hearer forms a comprehension-based belief that P (a belief based on taking another to have asserted that P) through the exercise of a (...) reliable competence to comprehend and filter assertive speech acts, then the hearer's belief is prima facie warranted. The paper discusses the psychology of comprehension, the function of assertion, and the evolution of filtering mechanisms, especially coherence checking. (shrink)

Martin Heidegger devotes extensive discussion to medieval philosophers, particularly to their treatment of Truth and Being. On both these topics, Heidegger accuses them of forgetting the question of Being and of being responsible for subjugating truth to the modern crusade for certainty: ‘truth is denied its own mode of being’ and is subordinated ‘to an intellect that judges correctly’. Though there are some studies that discuss Heidegger’s debt to and criticism of medieval thought, particularly that of Thomas Aquinas, there is (...) no constructive reply to his assertions. As a result, Heidegger’s critique had an unprecedented effect on the credibility of medieval philosophy, whereby great portions of the philosophical community dismiss it altogether as an illegitimate Onto‐Theology. It is the aim of this study to offer a constructive reply that will fundamentally grapple with these allegations. By constructive reply we mean not only a reply that avoids the problems Heidegger raises regarding existence, essence and truth, but more importantly, one that uses Heidegger’s criticism in order to present a more insightful account of these notions. The present study is composed of two parts where the second serves as a sort of addendum. The first part, the core of this study, is an attempt to develop an understanding of the distinction between essence and existence that, on the one hand, accords with Heidegger’s criticism while on the other hand advances our understanding of how we think and understand reality. After presenting Heidegger’s depiction of Aquinas’s distinction between essence and existence (esse) as a real distinction, the study will present several views propounded by scholars of Aquinas regarding the status of this distinction. It will be argued that it is not clear whether the distinction is real, formal or conceptual, and that different types of distinction are applied in different places, particularly in regard to the phantasm that Aquinas considers essential to the human act of thinking. The second part diverges from the first part and focuses on Heidegger’s criticism of Aquinas’s conception of truth as adequation, i.e., what it is that grounds the possibility of truth as adequation. This divergence is necessary in order to present a full metaphysical response to Heidegger’s criticism. Since the aim of the present study is to argue that Aquinas’s philosophical system can contend with Heidegger’s criticism, a partial reply would greatly diminish its effectiveness. (shrink)

In 'Perceptual Entitlement' (PPR 2003), Tyler Burge argues that on his teleological reliabilist account of perceptual warrant, warrant will persist in non-normal conditions, even radical skeptical scenarios like demon worlds. This paper explains why Burge's explanation falls short. But if we distinguish two grades of warrant, we can explain, in proper functionalist, teleological reliabilist terms, why warrant should persist in demon worlds. A normally functioning belief-forming process confers warrant in all worlds, provided it is reliable in normal conditions when functioning (...) normally. The first grade requires normal functioning. The second grade also requires being situated in normal conditions. (shrink)

Hylomorphism is the Aristotelian theory according to which substances are composed of matter and form. If a house is a substance, then its matter would be a collection of bricks and timbers and its form something like the structure of those bricks and timbers. It is widely agreed that matter bears a mereological relationship to substance; the bricks and timbers are parts of the house. But with form things are more controversial. Is the structure of the bricks and timbers best (...) conceived as a part of the house, or is it related to the house in some non-mereological fashion? Kathrin Koslicki argues that substances have formal parts, that forms are best conceived as bearing a mereological relation to substances. This paper shows that her argument fails, given the traditional and plausible distinction between substances and accidental unities. I close with a brief suggestion for a non-mereological construal of forms. (shrink)

This is the concluding chapter of a debate book about the existence of God: *Theism and Atheism: Opposing Arguments in Philosophy* (Gale, 2019). The book has a large number of contributors on both sides. My chapter suggests one way of unifying the contributions that are made on the atheistic side.

I examine two related arguments for the claim that if God is omnipotent, God cannot lack abilities such as the ability to do evil or to act irrationally. Both arguments concern the idea that omnipotence is inconsistent with being dominated with respect to abilities. I raise new issues in the formulation of such dominance principles about ability, and attempt to solve them. I also discuss and reject existing objections to these arguments. I conclude that these arguments are promising but not (...) conclusive, and that important work remains to be done in formulating the relevant dominance principles. (shrink)

Place-based education is founded on the idea that the student’s local community is one of their primary learning resources. Place-based education’s underlying educational principle is that students need to first have an experiential understanding of the history, culture, and ecology of the environment in which they are situated before tackling broader national and global issues. Such attempts are a step in the right direction in dealing with controversial issues in a democracy by providing resources for synthesising curriculum though theory (curriculum (...) content, including traditional subjects) and practice (practical learning as experiential education). Nevertheless, many place-based accounts discount Indigenous conceptions of place, which are integral to Indigenous ways of knowing, being and doing, especially in relation to the ontological relationship to Land and Country. Indigenous philosophy has the potential to inform what place-based education means by students developing a ‘sense of place’ when engaging with local communities as their ‘own’ place. In this article we re-imagine the community of inquiry as a place-responsive pedagogy by learning from Indigenous philosophy, and recentring Indigenous notions of place in experiential learning. In addition to exploring the pedagogical potential of a place-responsive account of the community of inquiry, we look to the implications for teacher preparation. (shrink)