OBJETIVO -/- O estudante de Zootecnia e de Veterinária, quando se depara com a produção animal, um dos pilares importantes é a reprodução, uma vez que é a perpetuação da espécie, seja para gerar filhas de uma vaca campeã em produção leiteira e de um touro com rusticidade e com aptidão produtiva de corte, ou mesmo para reposição de um plantel, o mesmo deve estar consciente de que esse ramo é de extrema responsabilidade, já que estará intimamente lidando com a (...) vida e com um investimento que pode gerar lucros em demasia para a propriedade ou, se mal feito o manejo da reprodução, trazer sérios transtornos para a mesma. -/- Nesse trabalho, o estudante revisará os sucessos da puberdade e estacionalidade reprodutiva relacionando-os com os processos endócrinos e os fatores que afetam sua manifestação como os nutricionais, para compreender a maneira ao qual podem ser manipuladas. -/- -/- • _____INTRODUÇÃO -/- A puberdade marca o início da vida reprodutiva do animal, permitindo integrar o indivíduo ao seu ciclo produtivo. A estacionalidade é uma característica de adaptação que algumas espécies desenvolveram para fazer garantir a eficiência da reprodução e a sobrevivência dos filhotes. -/- -/- • _____PUBERDADE -/- A puberdade é atingida quando o animal é capaz de produzir e liberar gametas viáveis e funcionais (férteis). Na fêmea esse fato ocorre na primeira ovulação, que geralmente coincide com a manifestação do comportamento do cio; e nos machos durante a primeira ejaculação com espermatozoides viáveis. -/- Do ponto de vista da produção animal, puberdade prematura ou precoce, é importante para poder permitir a incorporação dos animais ao ciclo produtivo o mais rapidamente possível. No caso de touros holandeses, por exemplo, é desejável que produzam sêmen precocemente para incorporá-los a prova de progênie; nas fêmeas, entretanto, deve-se considerar que nem sempre é conveniente usar o primeiro ciclo ou cio para reprodução. É o caso das marrãs (porcas primíparas), onde é benéfico esperar até o segundo ou terceiro estro para aumentar o tamanho da ninhada. Também pode ser vantajoso esperar que o indivíduo alcance sua maturidade sexual, que ocorre quando a fêmea consegue se reproduzir sem sofrer efeitos adversos. A ovelha nascida na primavera, por exemplo, pode engravidar no outono seguinte e dar à luz no primeiro ano de vida, mas seu crescimento pode ser afetado; o mesmo ocorre com a novilha, em que o acasalamento precoce pode promover distorcia por falta de desenvolvimento pélvico. -/- A puberdade é um processo gradual e está intimamente relacionada à taxa de crescimento e ao metabolismo energético. O recém-nascido usa energia para funções vitais, principalmente termorregulação; esse feito se deve ao fato de os jovens possuírem uma superfície corporal muito elevada em relação ao seu volume. Durante o desenvolvi-mento subsequente dos tecidos também há prioridade no uso de nutrientes, que inicialmente favorecem o desenvolvimento do tecido ósseo e muscular, e uma vez que estes atingem determinado tamanho de acordo com as condições genéticas do indivíduo, inicia-se o desenvolvimento do tecido adiposo, que é indicativa de um reservatório de energia. É importante ressaltar que existe uma interação entre a genética e o meio ambiente, de forma que o potencial genético só será expresso se o meio ambiente for favorável. -/- Para que a ovulação ocorra, é necessário considerar o funcionamento do eixo hipotálamo-hipófise-gonodal. O aumento da frequência pulsátil do GnRH hipotalâmico e em consequência do LH hipofisário provoca a maturação do folículo em nível gonodal, o que aumenta a produção de estrógenos. O aumento dos estrogênios causa, por feedback positivo no hipotálamo, a liberação do pico pré-ovulatório de LH e, consequentemente, a ovulação. Na fase pré-púbere, a frequência dos pulsos de GnRH e LH é muito baixa e insuficiente para provocar a maturação folicular, pois o hipotálamo é inibido e, portanto, não ocorre ovulação. -/- A geração pulsátil de GnRH no momento reprodutivo adequado para desencadear o início da puberdade depende de uma rede neural complexa que, além dos neurônios GnRH, inclui outros neurônios e células da glia; ele também integra vários sinais internos e externos para o corpo. A morfologia dos neurônios GnRH também é única, uma vez que seus dendritos também podem funcionar como axônios, dando-lhes uma função distinta. A geração de pulsos também indica a necessidade de sincronização entre subpopulações de neurônios GnRH, que, acima de tudo, parece ser extrínseca a esses neurônios e envolve múltiplos hormônios e neurotransmissores -/- Se dois níveis de conexões aferentes são considerados, estima-se que cada neurônio de GnRH pode ser conectado a cerca de cinco milhões de outros neurônios; milhares de genes, então, podem estar envolvidos no processo da puberdade. A importância funcional e hierárquica de cada um desses genes no controle dos neurônios GnRH, juntamente com outros fatores neuronais e gliais, pode diferir entre as espécies. Existem, no entanto, componentes fundamentais que parecem ser comuns a todos os mamíferos e que se situam nos níveis hierárquicos mais elevados, ajudando a compreender a progressão do processo puberal. Assim, todas as espécies de mamíferos estudadas, por exemplo, têm aglomerados de neurônios kisspeptinérgicos (que secretam kisspeptina), envolvidos na regulação da secreção tônica e secreção cíclica de GnRH, que também se classifica como o elemento mais alto na hierarquia desse complexo neuronal após considerar os neurônios GnRH. -/- Sabe-se que o eixo hipotálamo-hipofisário-gonodal está ativo desde as primeiras fases da vida do indivíduo, mesmo antes do nascimento em certas espécies. A secreção de GnRH, no entanto, é suprimida mais tarde no desenvolvimento e permanece dessa forma até o período pré-púbere, quando será reativada gradualmente. -/- Por várias décadas, a supressão e reinicialização dos pulsos de GnRH foi atribuída a uma hipótese conhecida como teoria gonadostat que afirma que o centro tônico do hipotálamo é inibido devido à sua sensibilidade ao mecanismo de feedback negativo dos esteroides gonodais, é aumentado; portanto, o GnRH e a consequente secreção de gonadotrofinas (FSH e LH) são insuficientes para a ocorrência da maturação folicular e espermatogênese. Essa sensibilidade diminui progressivamente à medida que a puberdade se aproxima. -/- Sabe-se agora que existem fatores não gonodais que agem em paralelo com os esteroides para mediar mudanças no feedback negativo que também são específicos da espécie. -/- Na fêmea, o centro gerador de pulso cíclico também deve ser considerado, o qual é responsável por iniciar a primeira ovulação. O centro cíclico é composto por uma segunda subpopulação de neurônios GnRH que é reativada por meio de uma complexa interação entre vários sistemas neuronais inibitórios (que devem reduzir progressiva-mente sua influência) e outros sistemas excitatórios, que, por sua vez, operam por meio de diferentes neurotransmissores, como o ácido γ-amino-butírico (GABA) e seus receptores, glutamato, óxido nítrico e neuropeptídio Y (NPY). Esses fatores, juntamente com as alterações morfológicas observadas nos neurônios do GnRH à medida que a puberdade se aproxima, e com as interações e sinais aferentes das células gliais, levam a um padrão de progressão linear que culminará na reativação do centro cíclico. Esse processo era conhecido anteriormente como teoria da maturação central e faz parte das mudanças que configuram o processo para chegar à puberdade. A elevação nas concen-trações de estradiol subsequente à reativação gradual do centro gerador de pulso tônico GnRH provavelmente permitirá a maturação final do centro cíclico. -/- A forma como cada organismo estabelece o momento certo para iniciar as mudanças que levam à puberdade é conhecido; a existência de algum mecanismo neurobiológico que constitui um relógio interno pode ser considerada. No entanto, esse mecanismo afetaria principalmente o desenvolvimento neuronal no nível central; também seria difícil compará-lo com a maneira pela qual fatores externos ao indivíduo afetam o início da puberdade. Nessa perspectiva, um sistema que permita receber informações completas sobre o crescimento e desenvolvimento do indivíduo poderia ser mais prático. Os mediadores desse sistema incluem o hormônio do crescimento, IGF-I, leptina e outros substratos metabólicos. A leptina em particular, que sinaliza as reservas de tecido adiposo, é um dos elementos mais importantes e, embora não determine quando começa a puberdade, se atua como fator permissivo para que o processo progrida, uma vez que excede um nível limite. A consideração do estágio de desenvolvimento do animal para o início da puberdade era anteriormente conhecida como o peso corporal crítico ou teoria do lipostato. É importante considerar que as três teorias mencionadas não são exclusivas. -/- O mecanismo da puberdade nos machos é semelhante ao já descrito; entretanto, deve-se lembrar que no macho o centro cíclico não está ativo. À medida que a puberdade se aproxima, o crescimento testicular é desencadeado e, em ruminantes e suínos, o pênis que estava preso à mucosa prepucial é gradualmente liberado. -/- -/- • _____FATORES QUE INFLUENCIAM A PUBERDADE -/- Os animais podem manifestar a puberdade de três formas diferentes. Pode ser tardia e o animal demorar para estar apto a reprodução; precoce e o animal entrar na vida reprodutiva antes do esperado ou pode ser normal e o animal estar com boa conformação e idade. Para tanto, alguns fatores podem interferir à manifestação da puberdade pelos animais como a genética, idade e peso, nutrição, fotoperíodo e o próprio manejo adotado. -/- -/- Genética -/- O genótipo afeta a idade da puberdade, pois algumas raças são anteriores a outras. Nos bovinos, as raças europeias atingem a puberdade antes dos zebuínos, isto é, uma novilha ou novilho da raça holandesa atinge a puberdade primeiro que os animais da mesma idade e do mesmo peso da raça nelore, por exemplo. -/- Da mesma forma, as porcas da raça chinesa Meishan atingem a puberdade por volta dos 115 dias de idade, metade da idade das raças brancas. As ovelhas de raças de corte, da mesma forma, são mais precoces que os produtores de lã. As raças pequenas, da mesma forma, são geralmente mais precoces, pelo menos em bovinos (jersey x guzerá) e em caninos. Os híbridos, por outro lado, apresentam puberdade mais precoce que os puros, devido ao efeito da heterose. Por este motivo, em certas espécies são utilizadas linhas híbridas. -/- -/- Idade e peso -/- A tabela 1 mostra a idade média de início da puberdade em espécies domésticas. O peso vivo (PV) adulto é mais relevante para a idade na puberdade nos ruminantes, enquanto em suínos é menos decisivo. A tabela também apresenta a porcentagem de peso corporal necessária para a puberdade ocorrer de forma natural. -/- -/- Tabela 1: Idade e peso a puberdade das espécies domésticas -/- Espécie -/- Fêmea (meses) -/- Macho (meses) -/- PV adulto (%) -/- Gado holandês -/- 11 (8-15) -/- 11 (7-18) -/- 30-40 -/- Gado brahman -/- 19 -/- 17 -/- 45-60 -/- Caprinos e ovinos -/- 7 (4-14) -/- 7 (6-9) -/- 40-60 -/- Suínos -/- 6 (5-7) -/- 7 (5-8) -/- 75 -/- Equinos -/- 18 (12-19) -/- 14 (10-24) -/- - -/- Caninos -/- 12 (6-24) -/- 9 (5-12) -/- - -/- Felinos -/- 8 (4-12) -/- 9 (8-10) -/- - -/- Fonte: VALENCIA, 2018. -/- Nutrição -/- Como a puberdade está relacionada à taxa de crescimento, os animais que recebem uma nutrição adequada e balanceada apresentarão puberdade em uma idade mais jovem, ou seja, mais precocemente; ao contrário, a puberdade será tardia nos animais que sofreram restrição alimentar, que estão desnutridos ou que tiveram seu crescimento afetado por doenças infecciosas ou parasitárias. A superalimentação também não é recomendada, pois pode alterar tanto os sinais que são recebidos pelo hipotálamo quanto sua resposta a eles. -/- Logo, o manejo alimentar adotado deve estar de acordo com as normas estabeleci-das pelos especialistas na área, principalmente no tocante as exigências nutricionais que devem servir de regra na propriedade. Sendo assim, os animais entrarão em puberdade com as taxas de alta qualidade o que afetará positivamente na prole futura e dará retorno lucrativo ao proprietário. -/- -/- Época do ano (Fotoperíodo) -/- Em fêmeas de espécies sazonais, como ovelhas e cabras, existem certos requisitos de fotoperíodo que devem ser atendidos para que a puberdade ocorra. Nessas espécies, um período de exposição a dias longos é necessário, seguido por outro de exposição a dias curtos. Na verdade, os cordeiros e cabritos nascidos fora da estação, mesmo que tenham atingido o peso necessário, terão que esperar até o outono seguinte (a estação reprodutiva) para atingir a puberdade. Os machos, por outro lado, não estão sujeitos a essas limitações nos requisitos fotoperiódicos para apresentar a puberdade. -/- Em novilhas nascidas no outono, por outro lado, a puberdade ocorre antes de um ano de idade, no verão seguinte ou no início do outono, mais cedo do que nas nascidas na primavera, devido à exposição a longos dias durante os primeiros seis meses do ano após seu nascimento aceleram seu crescimento. Em gatos, o aumento do fotoperíodo também acelera o início da puberdade. -/- Em ovelhas e novilhas, a primeira ovulação que ocorre ao entrar na puberdade é silenciosa; ou seja, não é acompanhada de sinais comportamentais de cio como a micção frequente, inchamento da vulva, uma montando a outra e deixando-se montar etc., pois para que esse comportamento se manifeste, o sistema nervoso necessita de uma pré-sensibilização com progesterona que não estará presente até o próximo ciclo, após o desenvolvimento do corpo lúteo vindo desta primeira ovulação. -/- -/- Sociossexual -/- A interação de indivíduos da mesma espécie ou a presença ou ausência de sinais de bioestimulação, como feromônios, pode afetar o período de puberdade. A puberdade, por exemplo, é atrasada em porcas criadas individualmente em comparação com porcas criadas em grupo. Além disso, na porca, ovelha e cabra, a exposição ao macho estimula as fêmeas e a puberdade aparece mais precocemente. -/- -/- Manejo -/- Certas práticas de manejo podem acelerar a puberdade, especialmente no período pré-púbere. Em porcas próximas à puberdade, por exemplo, o estresse causado por procedimentos, como o transporte de um local para outro ou a exposição ao macho, faz com que apareça o estro em torno de sete dias após a realização do manejo mencionado. -/- -/- • _____ESTACIONALIDADE REPRODUTIVA -/- A estacionalidade ou sazonalidade reprodutiva é uma estratégia evolutiva que se desenvolveu em algumas espécies; tende a tornar a reprodução mais eficiente. Nos países de latitudes distantes do equador, o objetivo é que as crias nasçam na primavera, época do ano mais favorável, graças à abundância de alimentos e às amenas condições climáticas. No caso da ovelha, cuja gestação dura cinco meses, para que os partos ocorram na primavera, ela deve engravidar no outono (figura 1), quando os dias são curtos; enquanto a égua, tendo uma gestação de aproximadamente 11 meses, deve conceber na primavera, quando os dias são longos; assim, o parto ocorrerá na primavera do ano seguinte (figura 2). -/- -/- Figura 1: Esquema ilustrativo da estacionalidade reprodutiva na espécie ovina. Fonte: PIRES et al., 2011. -/- -/- Esta característica evolutiva desenvolvida pela seleção natural na maioria das espécies silvestres e ainda é conservado por algumas espécies domésticas, como ovelhas, cabras, cavalos e gatos. Em bovinos e suínos, ao contrário, a domesticação levou à perda quase total da estacionalidade reprodutiva. -/- A estacionalidade reprodutiva é codificada nos genes; significa então que a seleção natural favoreceu a propagação de genes que permitiam acoplar a hora do nascimento com a melhor época do ano, por isso passou a ser considerada um método anticoncepcional natural. -/- -/- Figura 2: ciclo reprodutivo anual em espécies estacionais; onde são apresentados os períodos de gestação e a forma como se agrupam os nascimentos, independentemente da época reprodutiva da espécie, em vermelho as fêmeas estão apresentando estro ou cio. Fonte: VALENCIA, 2018. -/- -/- Fotoperíodo -/- Para sincronizar o período fértil com a época mais favorável do ano, a maioria das espécies sazonais usa o fotoperíodo (quantidade de luz diária ao longo do ano). -/- Este sinal ambiental é seguro, confiável e se repete a cada ano. Ovinos e caprinos se reproduzem na época do ano em que os dias são curtos e os equinos quando são longos. O grau de sazonalidade depende da origem da raça. As raças nativas de países localizados em latitudes elevadas (> 50°,ovelhas: soay, blackface, suffolk; cabras: saanen, alpino francês, toggenburg; equinos: puro-sangue, hanoveriano) terão uma estacionalidade mais acentuada do que as latitudes menores ou mediterrâneas (ovelhas: merino; cabras: murciana granadina; equinos: quarto de milha). Também existem raças de latitudes próximas ao Equador cuja estacionalidade é baixa ou nula (ovelhas: raças de pelo, crioulas; cabras: raças africanas e asiáticas) (tabela 2). -/- Para a maioria das raças de ovinos e caprinos, a estação reprodutiva começa no final do verão e início do outono; caracteriza-se pela apresentação de ciclos estrais sucessivos, e termina no final do inverno, quando se inicia o anestro, que se caracteriza pela ausência de ovulação. Nos equinos, ocorre o contrário, uma vez que a estação reprodutiva ocorre na primavera e no verão. -/- -/- Tabela 2: Relação entre a origem da raça e o grau de estacionalidade ou sazonalidade -/- Espécie -/- Alta -/- Média -/- Baixa -/- Ovinos -/- Suffolk, raças britânicas de lã e corte -/- Merino -/- Pelibuey, crioulas -/- Caprinos -/- Saanen, alpino, toggenburg -/- Murciana granadina -/- Crioula -/- Equinos -/- Puro-sangue, hanoveriano, quarto de milha -/- - -/- Crioula, burros -/- Fonte: VALENCIA, 2018. -/- -/- Mecanismo neuroendócrino da estacionalidade -/- Durante o período de anestro, o fotoperíodo exerce efeito inibitório sobre o centro tônico do GnRH no hipotálamo, diminuindo a frequência de pulso. Consequentemente, a pulsatilidade do LH também diminui, que agora é incapaz de induzir a maturação folicular, o aumento dos estrogênios, o pico pré-ovulatório de LH e, portanto, a ovulação. -/- Isso ocorre porque durante o anestro a sensibilidade do hipotálamo ao mecanismo de feedback negativo dos estrogênios e de outros fatores de origem não gonodal é aumentada. Ao aproximar-se da estação reprodutiva, a sensibilidade hipotalâmica diminui e o aumento da pulsatilidade do GnRH causa as mudanças que culminam na ovulação. Portanto, o mecanismo endócrino do anestro estacional é semelhante ao do anestro pré-púbere e de alguns outros tipos de anestro. -/- A estacionalidade é um bom exemplo da interação entre o meio ambiente e o sistema neuroendócrino, pois o organismo é capaz de traduzir um sinal externo ambiental, como o fotoperíodo, em um sinal hormonal interno, que neste caso é a melatonina. -/- A glândula pineal secreta melatonina durante as horas de escuridão. Os animais sazonais apresentam um ritmo reprodutivo endógeno, que é regulado por janelas de fotossensibilidade, determinadas por mudanças na duração do dia. O sinal luminoso é captado pela retina e conduzido, via nervo, pelo trato retino-hipotalâmico até o núcleo supraquiasmático, que funciona como o relógio biológico do corpo. Daí o sinal viaja para o núcleo para-ventricular, depois para o gânglio cervical e, finalmente, para a glândula pineal, que responde secretando melatonina (figura 3). -/- Nas ovelhas, a estação reprodutiva começa quando a duração do dia diminui e, naturalmente, a noite aumenta; na égua, ocorre quando os dias se alongam. -/- A primavera não é necessariamente a melhor época do ano em todas as regiões do globo. Nas latitudes tropicais, a primavera coincide com a seca e não com a abundância de forragem, aspecto a ser levado em consideração ao programar a reprodução. -/- Outro ponto importante a considerar é que as raças europeias sazonais mantêm sua estacionalidade no Brasil. -/- -/- Figura 3: Mecanismo do fotoperíodo em ovinos e a melatonina. Fonte: HAFEZ, 2004. -/- -/- Estacionalidade no macho -/- O macho é menos afetado que a fêmea pelas mudanças típicas de cada época do ano, já que sua função reprodutiva não é necessariamente interrompida durante o anestro ou repouso sexual, embora a produção de hormônios reprodutivos, tamanho e tônus testicular, a libido, as características qualitativas e quantitativas do ejaculado e a fertilidade do esperma podem ser diminuídas. O nível de afetação depende do grau de sazonalidade da raça e da latitude. 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CRC Press, 2001. -/- HAFEZ, Elsayed Saad Eldin; HAFEZ, Bahaa. Reprodução animal. São Paulo: Manole, 2004. -/- HUGHES, P. E.; PHILIP, G.; SISWADI, R. The effects of contact frequency and transport on the efficacy of the boar effect. Animal Reproduction Science, v. 46, n. 1-2, p. 159-165, 1997. -/- KARSCH, FRED J. et al. Neuroendocrine basis of seasonal reproduction. In: Proceedings of the 1983 Laurentian Hormone Conference. Academic Press, 1984. p. 185-232. -/- LINCOLN, G. A.; SHORT, R. V. Seasonal breeding: nature's contraceptive. In: Proceedings of the 1979 Laurentian Hormone Conference. Academic Press, 1980. p. 1-52. -/- MELLO, Raquel Rodrigues Costa. Puberdade e maturidade sexual em touros bovinos. Agropecuária Científica no Semiárido, v. 10, n. 3, p. 11-28, 2015. -/- MEZA‐HERRERA, C. A. et al. Neuroendocrine, metabolic and genomic cues signalling the onset of puberty in females. Reproduction in Domestic Animals, v. 45, n. 6, p. e495-e502, 2010. -/- MONTEIRO, Claudia Dias; BICUDO, Sony Dimas; TOMA, Hugo Shisei. Puberdade em fêmeas ovinas. Pubvet, v. 4, p. Art. 850-857, 2010. -/- OLIVEIRA, Daniel de Jesus Cardoso de. Mecanismos neuroendócrinos envolvidos na puberdade de novilhas da raça Nelore. 2006. Tese de Doutorado em Medicina Veterinária. Universidade de São Paulo. -/- OLSTER, DEBORAH H.; FOSTER, DOUGLAS L. Control of gonadotropin secretion in the male during puberty: a decrease in response to steroid inhibitory feedback in the absence of an increase in steroid-independent drive in the sheep. Endocrinology, v. 118, n. 6, p. 2225-2234, 1986. -/- PIRES, Bruno Carlos et al. Métodos para elevar o ritmo reprodutivo dos ovinos. PUBVET, Londrina, V. 5, N. 11, Ed. 158, Art. 1071, 2011. -/- PLANT, Tony M.; ZELEZNIK, Anthony J. (Ed.). Knobil and Neill's physiology of reproduction. New York: Academic Press, 2014. -/- RAMIREZ, Domingo V.; MCCANN, S. M. Comparison of the regulation of luteinizing hormone (LH) secretion in immature and adult rats. Endocrinology, v. 72, n. 3, p. 452-464, 1963. -/- ROSER, JANET F.; HUGHES, JOHN P. Seasonal effects on seminal quality, plasma hormone concentrations, and GnRH‐induced LH response in fertile and subfertile stallions. Journal of andrology, v. 13, n. 3, p. 214-223, 1992. -/- SALOMONI, Eduardo et al. Idade e peso à puberdade em fêmeas de corte puras e cruzas em campo natural. Pesquisa Agropecuária Brasileira, v. 23, n. 10, p. 1171-1179, 1988. -/- SMITH, Jeremy T.; CLARKE, Iain J. Seasonal breeding as a neuroendocrine model for puberty in sheep. Molecular and cellular endocrinology, v. 324, n. 1-2, p. 102-109, 2010. -/- VALENCIA, J. Pubertad y estacionalidad reproductiva. In. PORTA, L. R.; MEDRANO, J. H. H. Fisiología reproductiva de los animales domésticos. Cidade do México: FMVZ-UNAM, 2018. -/- WHITTEMORE, Colin et al. The science and practice of pig production. Blackwell Science Ltd, 1998. -/- -/- -/- FIXAÇÃO DO ASSUNTO -/- -/- 1. Defina o que é puberdade e como ela manifesta-se no corpo. -/- -/- -/- 2. Diferencie puberdade de maturidade sexual. -/- -/- -/- 3. Quais são os fenômenos que devem ser observados em fêmeas que estão entrando na puberdade? -/- -/- -/- 4. Qual o papel do GnRH e do IGF-I sobre a puberdade? -/- 5. Um produtor possui duas ovelhas e um carneiro reprodutor, as ovelhas possuem idade e peso, mas não manifestaram seu primeiro cio, quais elementos que você recomenda ao produtor para induzir a ciclicidade dessas fêmeas? -/- -/- -/- 6. De forma geral, quais os fatores que podem afetar a entrada na puberdade dos animais? -/- -/- -/- 7. Defina estacionalidade reprodutiva. -/- -/- -/- 8. O que é fotoperíodo e qual sua importância para a reprodução dos animais domésticos? -/- -/- -/- 9. Defina as relações existentes entre a origem da raça e o grau de estacionalidade e como tais teorias se aplicam ao rebanho brasileiro. -/- -/- -/- 10. Qual o papel da glândula pineal para a estacionalidade reprodutiva? -/- -/- -/- 11. Por que os machos são menos afetados pela sazonalidade reprodutiva do que as fêmeas? -/- -/- -/- 12. Sabendo-se sobre os termos de puberdade e estacionalidade e as características de ambos nas espécies domésticas, pede-se: um criador deseja obter 5 novas crias ovinas e 5 caprinas em seu plantel até o final do ano, para tanto ele ainda possui um ano e está na estação do verão, sabendo-se sobre a estacionalidade dessas espécies elabore um projeto reprodutivo de modo que essas 10 fêmeas possam gerar uma cria cada até a primavera. -/- -/- Dados: 10 fêmeas gerando 10 crias. 1 macho ovino e 1 caprino. Fêmeas com 1 ano de idade (2º cio) e peso corporal = 55% do peso adulto. Verão de 2020 para parir na primavera de 2020. (shrink)

Conspiracy theories are rather a popular topic these days, and a lot has been written on things like the meaning of _conspiracy theory_, whether it’s ever rational to believe conspiracy theories, and on the psychology and demographics of people who believe conspiracy theories. But very little has been said about why people might be led to posit conspiracy theories in the first place. This paper aims to fill this lacuna. In particular, I shall argue that, in open democratic societies, citizens (...) justifiably presuppose that the epistemic authorities—journalists, academics, scientists, and so on—are engaged in a good faith pursuit of the truth. This presupposition generates certain normative expectations on the behaviors of the epistemic authorities—they ought to be open to new evidence, possess a healthy degree of skepticism, be willing to engage with opponents, and so on. So, when an epistemic authority is presented with some putatively anomalous data or an alternative hypothesis for some event or phenomena, people expect the epistemic authority to respond in a way that is consonant with these norms. In some instances, however, the epistemic authorities do not respond in this way and instead are dogmatic, dismissive, and engage in _ad hominem_. From the point of view of the citizen, there’s a tension here between how the epistemic authorities ought to behave and how they have, in fact, behaved which is best resolved either by taking the epistemic authorities less seriously or by positing a conspiracy theory. Put another way, the failure of the epistemic authorities to adhere to the norms by which we take them to be governed when presented with apparent anomalies or alternative hypotheses is one reason for which one might initially posit a conspiracy theory. (shrink)

We offer a general framework for theorizing about the structure of knowledge and belief in terms of the comparative normality of situations compatible with one’s evidence. The guiding idea is that, if a possibility is sufficiently less normal than one’s actual situation, then one can know that that possibility does not obtain. This explains how people can have inductive knowledge that goes beyond what is strictly entailed by their evidence. We motivate the framework by showing how it illuminates knowledge about (...) the future, knowledge of lawful regularities, knowledge about parameters measured using imperfect instruments, the connection between knowledge, belief, and probability, and the dynamics of knowledge and belief in response to new evidence. (shrink)

When should you engage with difficult arguments against your cherished controversial beliefs? The primary conclusion of this book is that your obligations to engage with counterarguments are more limited than is often thought. In some standard situations, you shouldn't engage with difficult counterarguments and, if you do, you shouldn't engage with them open-mindedly. This conclusion runs counter to aspects of the Millian political tradition and political liberalism, as well as what people working in informal logic tend to say about argumentation. (...) -/- Not all misleading arguments wear their flaws on their sleeve. Each step of a misleading argument might seem compelling and you might not be able to figure out what's wrong with it. Still, even if you can't figure out what's wrong with an argument, you can know that it's misleading. One way to know that an argument is misleading is, counterintuitively, to lack expertise in the methods and evidence-types employed by the argument. When you know that a counterargument is misleading, you shouldn't engage with it open-mindedly and sometimes shouldn't engage with it at all. You shouldn't engage open-mindedly because you shouldn't be willing to reduce your confidence in response to arguments you know are misleading. And you sometimes shouldn't engage closed-mindedly, because to do so can be manipulative or ineffective. -/- In making this case, Jeremy Fantl discusses echo chambers and group polarization, the importance in academic writing of a sympathetic case for the opposition, the epistemology of disagreement, the account of open-mindedness, and invitations to problematic academic speakers. (shrink)

How is what we believe related to how we act? That depends on what we mean by ‘believe’. On the one hand, there is what we're sure of: what our names are, where we were born, whether we are sitting in front of a screen. Surety, in this sense, is not uncommon — it does not imply Cartesian absolute certainty, from which no possible course of experience could dislodge us. But there are many things that we think that we are (...) not sure of. For example, you might think that it will rain sometime this month, but not be sure that it will. Both what we're sure of and what we think have important normative connections to action. But the connections are quite different. This paper explores these issues with respect to assertion, inquiry, and decision making. We conclude by arguing that there is no theoretically significant notion of ‘full belief’ intermediate in strength between thinking and being sure. (shrink)

Perception solves computationally demanding problems at lightning fast speed. It recovers sophisticated representations of the world from degraded inputs, often in a matter of milliseconds. Any theory of perception must be able to explain how this is possible; in other words, it must be able to explain perception's computational tractability. One of the few attempts to move toward such an explanation has been the information encapsulation hypothesis, which posits that perception can be fast because it keeps computational costs low by (...) forgoing access to information stored in cognition. I argue that we have no compelling reason to believe that encapsulation explains (or even contributes to an explanation of) perceptual tractability, and much reason to doubt it. This is because there exist much deeper computational challenges for perception than information access, and these threaten to make the costs of access irrelevant. If this is right, it undermines a core computational motivation for encapsulation and sends us back to the drawing board for explanations of perceptual tractability. (shrink)

Plato is often acknowledged as the first philosophical critic of democracy and his Republic is regularly taken as a paradigm of an anti-democratic work. While it is true that Plato objected to much about the democracy of his own time, Plato’s political theorizing also reveals an interest in improving democratic institutions. This chapter explores three themes in Plato’s thinking about democracy: firstly, Plato's insistence that rulers should be knowledgeable and his claim that most people are politically incompetent (§1); secondly, Plato's (...) criticisms of oratory and the corrupting effects of public rhetoric (§2); thirdly, Plato's use of democratic institutions in the Laws (§3). Once we appreciate these different evaluations of democratic practices, we can see that Plato was not simply ‘anti-democratic’ or ‘pro-democratic’ but thought some democratic practices should be abandoned, some reformed, and some adopted. (shrink)

Consider the sentence “Lois knows that Superman flies, but she doesn’t know that Clark flies”. In this paper we defend a Millian contextualist semantics for propositional attitude ascriptions, according to which ordinary uses of this sentence are true but involve a mid-sentence shift in context. Absent any constraints on the relevant parameters of context sensitivity, such a semantics would be untenable: it would undermine the good standing of systematic theorizing about the propositional attitudes, trivializing many of the central questions of (...) epistemology, the philosophy of mind, and the philosophy of action. In response to this problem, we prove a series of tenability results. We show that, given certain constraints on the parameters of context sensitivity, there is a broad class of principles of propositional attitude psychology whose good standing follows from corresponding claims about people’s mental representations. But these constraints also have some surprising consequences: they are jointly incompatible with coarse-grained theories of propositions, and they are in tension with a natural picture of how speakers and hearers coordinate on the interpretation of attitude ascriptions. In light of these consequences we explore different ways in which the contextualist picture might be developed, and argue that our preferred way compares favorably with Fregeanism and neo-Russellianism. (shrink)

Thomas Reid (1710–96) is increasingly being seen as a highly significant philosopher and a central figure in the Scottish Enlightenment. This new edition of Reid's classic philosophical text in the philosophy of mind at long last gives scholars a complete, critically edited text of the Inquiry. The critical text is based on the fourth life-time edition (1785). A selection of related documents showing the development of Reid's thought, textual notes, bibliographical details of previous editions and a full introduction by the (...) editor makes this an important contribution to the study of this increasingly respected philosopher. -/- Key Features - Complete, critically edited text of the Inquiry accompanied by a judicious selection of manuscript evidence relating to its composition - Comprehensive Introduction providing an historical and philosophical account of the formation of the Inquiry - Detailed textual notes which include bibliographical details and allusions, translations, references to secondary literature and selected passages from Reid's manuscripts. (shrink)

We characterize a type of functional explanation that addresses why a homologous trait originating deep in the evolutionary history of a group remains widespread and largely unchanged across the group’s lineages. We argue that biologists regularly provide this type of explanation when they attribute conserved functions to phenotypic and genetic traits. The concept of conserved function applies broadly to many biological domains, and we illustrate its importance using examples of molecular sequence alignments at the intersection of evolution and cell biology. (...) We use these examples to show how the study of conserved functions can integrate knowledge of a trait’s causal effects on fitness and its history of natural selection without invoking adaptation. We also show how conserved function provides a novel basis for addressing objections against evolutionary functions raised by Robert Cummins. (shrink)

Some people feel distressed reflecting on human extinction. Some people even claim that our efforts and lives would be empty and pointless if humanity becomes extinct, even if this will not occur for millions of years. In this essay, I will attempt to demonstrate that this claim is false. The desire for long-lastingness or quasi-immortality is often unwittingly adopted as a standard for judging whether our efforts are significant. If we accomplish our goals and then later in life conclude that (...) these accomplishments were of no significance, then this is a sign that the desire for long-lastingness has crept into our standards. By recognizing this, and refraining from adopting an unreasonable standard to judge whether our efforts are significant, it will be to our advantage. Then, when we look back on life from an external perspective that encompasses times after humanity has become extinct, we will not conclude that our efforts amounted to nothing. Rather, we will conclude that many people made significant accomplishments that made their lives and the lives of other people better than they would have been if their goals had never been pursued. (shrink)

What explains why we are subjects for whom objects can have value, and what explains which objects have value for us? Axiologicians say that the value of humanity is the answer. I argue that our value, no matter what it is like, cannot perform this task. We are animals among others. An explanation of the value of objects for us must fit into an explanation of the value of objects for animals generally. Different objects have value for different animals. Those (...) differences depend on differences in animal natures and, in particular, on the diverse characteristic capacities of different animals. Once we invoke animal natures, there is nothing for the value of animality, including the value of humanity, to explain. (shrink)

In his book, The Human Predicament, David Benatar claims that our individual lives and human life, in general, do not make a difference beyond Earth and, therefore, are meaningless from the vast, cosmic perspective. In this paper, I will explain how what we do matters from the cosmic perspective. I will provide examples of how human beings have transcended our limits, thereby giving human life some meaning from the cosmic perspective. Also, I will argue that human life could become even (...) more meaningful by making some fundamental achievements, such as determining how life originated. (shrink)

This chapter offers an opinionated introduction to higher-order formal languages with an eye towards their applications in metaphysics. A simply relationally typed higher-order language is introduced in four stages: starting with first-order logic, adding first-order predicate abstraction, generalizing to higher-order predicate abstraction, and finally adding higher-order quantification. It is argued that both β-conversion and Universal Instantiation are valid on the intended interpretation of this language. Given these two principles, it is then shown how we can use pure higher-order logic to (...) ask, and begin to answer, metaphysical questions with non-trivial implications. In particular, while we must reject the popular idea that structural differences between sentences correspond to parallel distinctions in the logical structure of extra-linguistic reality, it may still be possible to give a purely logical characterization of objectual aboutness and related notions. (shrink)

Wilfrid Sellars’s ethical theory was rich and deeply innovative. On Sellars’s view, moral judgments express a special kind of shared intention. Thus, we should see Sellars as an early advocate of an expressivism of plans and intentions, and an early theorist of collective intentionality. He supplemented this theory with a sophisticated logic of intentions, a robust theory of the categorical validity of normative expressions, a subtle way of reconciling the cognitive and motivating aspects of moral judgment, and much more— all (...) within a strict nominalism that preserves Sellars’s commitment to naturalism. The Ethics of Wilfrid Sellars offers the first systematic treatment of this sadly neglected aspect of Sellars’s work and demonstrates that his ethical theory— just like his more widely discussed epistemology— has much to contribute to current debates. (shrink)

Criminal justice is primarily designed to serve the public interest in relation to criminal acts. Restorative justice is designed to address the harm-related needs of individuals in the aftermath of wrongdoing. These distinct aims require such different processes and priorities that any attempt to integrate restorative justice within the criminal justice system will almost invariably undermine the quality and effectiveness of both. In this book, the author argues that the optimal relationship between the two should therefore be one of maximum (...) independence: the instruments of the state should not be used to impose or enforce the decision to participate in restorative justice, any component of the restorative justice process or its outcome. It is also suggested that, in the absence of legislative innovation, this kind of separation is likely to require that restorative justice is situated after a case has actually exited the justice system, or after it has, in legal terms, effectively done so, as in a post-sentence context. [Note: The publisher offers a 40% discount on this book (conditions apply). Please see the author's website: "Relational Approaches" for details.]. (shrink)

Proponents of the rule of law argue about whether that ideal should be conceived formalistically or in terms of substantive values. Formalistically, the rule of law is associated with principles like generality, clarity, prospectivity, consistency, etc. Substantively, it is associated with market values, with constitutional rights, and with freedom and human dignity. In this paper, I argue for a third layer of complexity: the procedural aspect of the rule of law; the aspects of rule-of-law requirements that have to do with (...) "natural Justice" or "procedural due process." These I believe have been neglected in the jurisprudential literature devoted specifically to the idea of the rule of law and they deserve much greater emphasis. Moreover procedural values go beyond elementary principles like the guarantee of an unbiased tribunal or the opportunity to present and confront evidence. They include the right to argue in a court about what the law is and what its bearing should be on one's situation. The provision that law makes for argument is necessarily unsettling, and so this emphasis on the procedural aspect highlights the point predictability should not be regarded as the be-all and end-all of the rule of law. (shrink)

Philosophers of science have insisted that evidence of underlying mechanisms is required to support claims about the effects of medical interventions. Yet evidence about mechanisms does not feature on dominant evidence-based medicine “hierarchies.” After arguing that only inferences from mechanisms (“mechanistic reasoning”)—not mechanisms themselves—count as evidence, I argue for a middle ground. Mechanistic reasoning is not required to establish causation when we have high-quality controlled studies; moreover, mechanistic reasoning is more problematic than has been assumed. Yet where the problems can (...) be overcome, mechanistic reasoning can and should be used as evidence. (shrink)

This essay develops a framework for understanding what I call the ethics of reflexivity, that is, the norms that govern attitudes and actions with respect to one’s own worth. I distinguish five central aspects of the reflexive commitment to living in accordance with one’s personal ideals: the extent to which and manner in which one regards oneself from an evaluative point of view, the extent to which one cares about receiving the respect of others, the degree to which one interprets (...) one’s personal ideals in an individualistic or collective manner, the degree to which one’s commitment to living in accordance with one’s personal ideals is rigid or flexible, and the worthiness of one’s personal ideals. This framework, I argue, illuminates the nature and moral significance of virtuous and vicious forms of the character trait of pride. (shrink)

We show that, contrary to conventional wisdom, Frege’s distinction between sense and reference does not reconcile a classical logic of identity with apparent counterexamples to it involving proper names embedded under propositional attitude verbs.

Did Plato intend the laws of the Laws to change? While most scholars agree that there is to be legal change in Magnesia, I contend that this issue has been clouded by confusing three distinct questions: (1) whether there are legal mechanisms for changing the law in Magnesia, (2) what the attitudes of Magnesian citizens towards innovation and legal change are, and (3) whether Plato thinks the law is always the ultimate political authority. Once we separate these issues and look (...) at the relevant texts more closely, we see that the Athenian Visitor is primarily concerned with supplementing the original lawgiver’s laws and that any innovation that occurs should be consistent with this lawcode. This does not settle the question about whether it is always right to act in accordance with the existing laws, though it does provide a valuable framework for understanding a central aspect of Platonic political philosophy. Thus, although Plato’s ideal places knowledge above the law, in practice the laws of Magnesia will be fixed and authoritative for those people living under them. (shrink)

Is the exemplar of modern ethical theory estranged from their intimates because the motive of duty dominates their motivational psychology? While this challenge against modern ethical theory is familiar, I argue that with respect to a certain strand of Kantian ethical theory, it does not so much as make sense. I explain the content and functional role of the motive of duty in the psychology of the moral exemplar, stressing in particular how that motive shapes and informs the content of (...) others, including those characteristic of intimacy. I argue that to the extent that a subject does not integrate their motive of duty with their other motives, their moral and intimate relationships are compromised, and on the same grounds, because intimate relationships are interpersonal relationships and the motive of duty just is the motive to respect another person as a separate person. (shrink)

It's often said that according to deflationary theories of truth, truth is not a ‘substantial’ property. While this is a fine slogan, it is far from transparent what deflationists mean (or ought to mean) in saying that truth is ‘insubstantial’. Focusing so intently upon the concept of truth and the word ‘true’, I argue, deflationists and their critics have been insufficiently attentive to a host of metaphysical complexities that arise for deflationists in connection with the property of truth. My aim (...) is to correct several misunderstandings as to what deflationists are after here—including some harboured by deflationists themselves—and to offer an account of the commitments about truth's nature that they ought to undertake. In developing this account, I focus particularly upon the issue of what metaphysics of truth a Horwichian minimalist ought to adopt. (shrink)

The theories of cultural anthropologist Ernest Becker arise from an existential and psychological analysis of the death terror/anxiety deep in the unconscious of every human. Becker details how this anxiety governs the ideologies and behaviors of our species—something now confirmed by thousands of experiments performed by psychologists engaged in contemporary terror management theory (TMT). Humans manage their anxiety through what Becker terms “hero systems”—concepts, beliefs, and myths we create to give us a sense of significance and meaning during, and even (...) beyond our mortal lives. Today, many dominant economic, technological, and religious hero systems seek to confirm our significance by denying that we are—like all other species—animals who must exist in a decaying, mortal body. Becker shows how this attempt to deny our “creatureliness” (basic biological nature) causes humans to stand against the natural world we are embedded in, leading to an assault on the planet and nonhuman animals. As a result, Becker believed pacifism was the only hero system capable of keeping humankind from destroying itself and the earth. Pacifism is the precursor to the more encompassing ethical concept of “reverence for life,” advocated by Dr. Albert Schweitzer. By respecting the will-to-live in all sentient beings, reverence for life transcends concern for humans alone and extends moral and physical safeguards to life as such. Confronting the fact that humans are increasingly alienated from their commodified world and their own being, reverence for life stands as a vital solution to many of our modern problems. And following contemporary TMT research, reverencing life can also expand one’s self-esteem, which research shows lowers death anxiety, reduces aggression, and offers authentic meaning to life itself. (shrink)

The purpose of this survey was to gather individual’s attitudes and feelings towards privacy and the selling of data. A total (N) of 1,107 people responded to the survey. -/- Across continents, age, gender, and levels of education, people overwhelmingly think privacy is important. An impressive 82% of respondents deem privacy extremely or very important, and only 1% deem privacy unimportant. Similarly, 88% of participants either agree or strongly agree with the statement that ‘violations to the right to privacy are (...) one of the most important dangers that citizens face in the digital age.’ The great majority of respondents (92%) report having experienced at least one privacy breach. -/- People’s first concern when losing privacy is the possibility that their personal data might be used to steal money from them. Interestingly, in second place in the ranking of concerns, people report being concerned about privacy because ‘Privacy is a good in itself, above and beyond the consequences it may have.’ -/- People tend to feel that they cannot trust companies and institutions to protect their privacy and use their personal data in responsible ways. The majority of people believe that governments should not be allowed to collect everyone’s personal data. Privacy is thought to be a right that should not have to be paid for. (shrink)

What can Stoicism offer to contemporary debates about forgiveness? Given their outright rejection of a reactive attitudes framework for responding to wrongdoing and their bold suggestions of how to revise our moral practices, the Stoics provide a valuable lens through which to re-evaluate various central claims in the debates about forgiveness. In this chapter, I highlight four common assumptions that the Stoics would consider problematic: firstly, that forgiveness is opposed to justice; secondly, that anger and resentment are necessary for registering (...) wrongdoing; thirdly, that anger and resentment are generally reliable at tracking the severity of wrongdoing; fourthly, that reconciliation with wrongdoers is an option rather than an imperative of virtue. Insofar as the Stoics provide defensible and often compelling alternatives to these positions, Stoicism offers a number of philosophical resources to re-conceptualize the way we think about forgiveness and suggests ways in which forgiveness might be better integrated into a virtue ethical framework. (shrink)

Introduction Current treatments for pain have limited benefits and worrying side effects. Some studies suggest that pain is reduced when clinicians deliver positive messages. However, the effects of positive messages are heterogeneous and have not been subject to meta-analysis. We aimed to estimate the efficacy of positive messages for pain reduction. -/- Methods We included randomized trials of the effects of positive messages in a subset of the studies included in a recent systematic review of context factors for treating pain. (...) Several electronic databases were searched. Reference lists of relevant studies were also searched. Two authors independently undertook study selection, data extraction, risk of bias assessment, and analyses. Our primary outcome measures were differences in patient- or observer-reported pain between groups who were given positive messages and those who were not. -/- Results Of the 16 randomized trials (1703 patients) that met the inclusion criteria, 12 trials had sufficient data for meta-analysis. The pooled standardized effect size was −0.31 (95% confidence interval [CI] −0.61 to −0.01, p = 0.04, I2 = 82%). The effect size remained positive but not statistically significant after we excluded studies considered to have a high risk of bias (standard effect size −0.17, 95% CI −0.54 to 0.19, P = 0.36, I2 = 84%). -/- Conclusion Care of patients with chronic or acute pain may be enhanced when clinicians deliver positive messages about possible clinical outcomes. However, we have identified several limitations of the present study that suggest caution when interpreting the results. We recommend further high-quality studies to confirm (or falsify) our result. -/- FUNDING -/- Alexander Mebius research has been funded through the ERC grant "Philosophy of Pharmacology: Safety, Statistical Standards, and Evidence Amalgamation" (GA: 639276). (shrink)

In this paper, we offer a brief, critical survey of contemporary work on truth. We begin by reflecting on the distinction between substantivist and deflationary truth theories. We then turn to three new kinds of truth theory—Kevin Scharp's replacement theory, John MacFarlane's relativism, and the alethic pluralism pioneered by Michael Lynch and Crispin Wright. We argue that despite their considerable differences, these theories exhibit a common "pluralizing tendency" with respect to truth. In the final section, we look at the underinvestigated (...) interface between metaphysical and formal truth theories, pointing to several promising questions that arise here. (shrink)

Functionalism about truth, or alethic functionalism, is one of our most promising approaches to the study of truth. In this chapter, I chart a course for functionalist inquiry that centrally involves the empirical study of ordinary thought about truth. In doing so, I review some existing empirical data on the ways in which we think about truth and offer suggestions for future work on this issue. I also argue that some of our data lend support to two kinds of pluralism (...) regarding ordinary thought about truth. These pluralist views, as I show, can be straightforwardly integrated into the broader functionalist framework. The main result of this integration is that some unexplored metaphysical views about truth become visible. To close the chapter, I briefly respond to one of the most serious objections to functionalism, due to Cory Wright. (shrink)

Now, Kingfisher was tired of eating fish every day. One day, he decided to try something new and went on a hunt for frogs. After a few attempts, Kingfisher finally caught a frog and was excited to try it.

Most people who defend physician-assisted death (PAD) endorse the Joint View, which holds that two conditions—autonomy and welfare—must be satisfied for PAD to be justified. In this paper, we defend an Autonomy Only view. We argue that the welfare condition is either otiose on the most plausible account of the autonomy condition, or else is implausibly restrictive, particularly once we account for the broad range of reasons patients cite for desiring PAD, such as “tired of life” cases. Moreover, many of (...) the common objections to an Autonomy Only view fail once we understand the extent of the autonomy condition’s requirements—in particular, the importance of one’s values for autonomous choices. If our view is correct, then the scope of permissible PAD is broader than is currently accepted in both the philosophical literature and the law, and therefore poses an important challenge to this widely accepted view on justified PAD. (shrink)

Conditional excluded middle (CEM) is the following principe of counterfactual logic: either, if it were the case that φ, it would be the case that ψ, or, if it were the case that φ, it would be the case that not-ψ. I will first show that CEM entails the identity of indiscernibles, the falsity of physicalism, and the failure of the modal to supervene on the categorical and of the vague to supervene on the precise. I will then argue that (...) we should accept these startling conclusions, since CEM is valid. (shrink)

Picturing is a poorly understood element of Sellars’s philosophical project. We diagnose the problem with picturing as follows: on the one hand, it seems that it must be connected with action in order for it to do its job. On the other hand, the representational states of a picturing system are characterized in descriptive and seemingly static terms. How can static terms be connected with action? To solve this problem, we adopt a concept from recent work in Sellarsian metaethics: the (...) idea of a material practical inference, which (we argue) features centrally in how we picture. The key distinction is that the picturing of nonhuman animals involves only Humean material practical inference, in which representational states are corrected only by feedback from the environment and not from discursive interactions. The resulting view shows that Sellars’s contributions to practical philosophy (especially theory of action and metaethics) cannot be separated from his contributions to philosophy of mind, language, and cognitive science. Further, the view makes it clear that picturing is neither a version of the Given, nor is it a fifth wheel to inferential role in explaining representation, but is essential to Sellars’s model of how animals—including humans—represent their environment. (shrink)

This chapter addresses concerns that pragmatic encroachers are committed to problematic knowledge variance. It first replies to Charity Anderson and John Hawthorne’s new putative problem cases, which purport to show that pragmatic encroachment is committed to problematic variations in knowledge depending on what choices are available to the potential knower. It argues that the new cases do not provide any new reasons to be concerned about the pragmatic encroacher’s commitment to knowledge-variance. The chapter further argues that concerns about knowledge-variance are (...) not limited to the pragmatic encroacher, but come up for traditional purist invariantism as well. (shrink)

What is the function of morality—what is it all about? What is the basis of morality—what explains our moral agency and patiency? This essay defends a unique Kantian answer to these questions. Morality is about securing our independence from each other by giving each other equal discretion over whether and how we interact. The basis of our moral agency and patiency is practical reason. The first half addresses objections that this account cannot explain the moral patiency of beings who are (...) not also moral agents such as infantile, elderly, and infirm human beings and the other animals who are not moral agents. The second half argues that this account is preferable, on grounds of consistency with the basic Kantian account of the function and content of morality, to the familiar account of our moral patiency, popular especially though not exclusively with contemporary Kantians, in terms of the value of humanity. (shrink)

This paper provides a method for characterizing space events using the framework of conceptual spaces. We focus specifically on estimating and ranking the likelihood of collisions between space objects. The objective is to design an approach for anticipatory decision support for space operators who can take preventive actions on the basis of assessments of relative risk. To make this possible our approach draws on the fusion of both hard and soft data within a single decision support framework. Contextual data is (...) also taken into account, for example data about space weather effects, by drawing on the Space Domain Ontologies, a large system of ontologies designed to support all aspects of space situational awareness. The framework is coupled with a mathematical programming scheme that frames a mathematically optimal approach for decision support, providing a quantitative basis for ranking potential for collision across multiple satellite pairs. The goal is to provide the broadest possible information foundation for critical assessments of collision likelihood. (shrink)

In this paper, I argue that forgiveness is a morally appropriate response only when it is grounded in the wrongdoer’s demonstration of genuine remorse, their offer of a sincere apology, and, where appropriate, acts of recompense and behavioral change. I then respond to John Kleinig’s suggestion (in his paper “Forgiveness and Unconditionality”) that when an apology is not forthcoming, there are at least three additional grounds that, when motivated by virtues such as love and compassion, could nevertheless render “unconditional forgiveness” (...) a morally laudable option. I argue that such grounds could indeed constitute or result in laudable responses to wrongdoing, but only if they are not conceived of or described in terms of forgiveness. (shrink)

In this paper, I discuss two concerns for pluralist truth theories: a concern about a key detail of these theories and a concern about their viability. The detail-related concern is that pluralists have relied heavily upon the notion of a domain, but it is not transparent what they take domains to be. Since the notion of a domain has been present in philosophy for some time, it is important for many theorists, not only truth pluralists, to be clear on what (...) domains are and what work they can do. The viability-related concern is that it’s not clear how a pluralist truth theory could explain the truth-conditions of mixed atomic propositions. To address this concern, truth pluralists should recognize something to which they have not been sufficiently attentive: that some atomic propositions belong to more than one domain. But, recognizing this requires rethinking the relationships between the nature of propositions, their membership in domains, and their truth. I address these issues and propose an understanding of them that is preferable to the best existing account of them, that offered by Michael Lynch. (shrink)

Scholars have wrestled with "consciousness", a major scholar calling it the "hard problem". Some thirty-plus years after the Towards a Science of Consciousness, we do not seem to be any closer to an answer to "What is consciousness?". Seemingly irresolvable metaphysical problems are addressed by bootstrapping, provisional assumptions, not unlike those used by logicians and mathematicians. I bootstrap with the same ontology and epistemology applicable to everything we apprehend. Here, I argue for a version of the unity of opposites, a (...) form of neutral monism. Something exists because of what it is not; nothing can exist by itself, singularities (analogous to monads), expressing the model. Applying this most fundamental law to the consciousness problem, the physical (movement) comes into being simultaneously as the mental (stasis), each displayed by a field that is variegated (ranging from creative to entropic processes). Such is in keeping with how the singularity emerged as our universe, the same form that may account for sub-Planck-scale phenomena. Overall, like the most fundamental law, deep structures are imminent in our universe, both as objects and processes. (shrink)

When pessimists claim that human life is meaningless, they often also assert that the universe is “blind to good and evil” and “indifferent to us”. How, if it all, is the indifference of the universe relevant to whether life is meaningful? To answer this question, and to know whether we should be concerned that the universe is indifferent, we need a clearer and deeper understanding of the concept of “cosmic indifference”, which I will seek to provide. I will argue that (...) the lives of many individuals are meaningful and that human life, in general, is somewhat meaningful, despite the indifference of the universe. Furthermore, I will seek to demonstrate that even if the universe cared about us, or had preferences for how we live our lives, that this likely would not enhance the quality of our lives. (shrink)

We argue that knowledge doesn‘t require any of truth, justification, or belief. This is so for four primary reasons. First, each of the three conditions has been subject to convincing counterexamples. In addition, the resultant account explains the value of knowledge, manifests important theoretical virtues (in particular, simplicity), and avoids commitment to skepticism.

A movement dedicated to applying neuroscience to traditional philosophical problems and using philosophical methods to illuminate issues in neuroscience began about twenty-five years ago. Results in neuroscience have affected how we see traditional areas of philosophical concern such as perception, belief-formation, and consciousness. There is an interesting interaction between some of the distinctive features of neuroscience and important general issues in the philosophy of science. And recent neuroscience has thrown up a few conceptual issues that philosophers are perhaps best trained (...) to deal with. After sketching the history of the movement, we explore the relationships between neuroscience and philosophy and introduce some of the specific issues that have arisen. (shrink)

This paper explores the feasibility of offering a restorative justice (RJ) approach in cases of domestic violence (DV). I argue that widely used RJ processes—such as ‘conferencing’—are unlikely to be sufficiently safe or effective in cases of DV, at least as these processes are standardly designed and practiced (Sections 1-6). I then support the view that if RJ is to be used in cases of DV, then new specialist processes will need to be co-designed with key stakeholders to ensure they (...) embody not only RJ principles, but also feminist theory and the concept of transformative justice (Section 7). (shrink)

This paper investigates a generalization of Boolean algebras which I call agglomerative algebras. It also outlines two conceptions of propositions according to which they form an agglomerative algebra but not a Boolean algebra with respect to conjunction and negation.

Can testimony provide reasons to believe some proposition about an artwork’s aesthetic character? Can testimony bring an agent into a position where they can issue an aesthetic judgement about that artwork? What is the epistemic value of aesthetic communication? These questions have received sustained philosophical attention. More fundamental questions about aesthetic communication have meanwhile been neglected. These latter questions concern the nature of aesthetic communication, the criteria that determine when aesthetic communication is successful, and the frequency of communicative success in (...) aesthetic communication. The neglect of these questions is a serious oversight, not least because they bear directly on each of the other questions listed. This paper’s focus is the more fundamental set of questions. I argue for a restricted form of communicative pessimism. Discerning aesthetic communication about an artwork typically fails unless its recipient is both acquainted with that artwork and able to coordinate with the speaker on an aesthetic understanding of it. I arrive at this conclusion by challenging the standard conception of the nature of aesthetic communication that the literature presupposes, as well as an accompanying criterion of communicative success. I introduce an alternative view. In closing I relate my discussion to the former set of questions. (shrink)

Most of us believe that partiality applies in a broad range of relationships. One relationship on which there is much disagreement is co-nationality. Some writers argue that co-national partiality is not justified in certain cases, like killing in war, since killing in defense of co-nationals is intuitively impermissible in other contexts. I argue that this approach overlooks an important structural feature of partiality—namely, that its scope is sometimes restricted. In this essay, I show how some relationships that generate reasons of (...) partiality are restricted in scope—that is, they generate reasons within particular contexts or with respect to particular goods. I then argue that co-national partiality is scope restricted. I then show how this fact helps proponents of co-national partiality overcome the aforementioned objection to its application in cases like war. (shrink)

Part of Plato’s complaint about the cognitive status of art cites the pollution of aesthetic cognition by the affective side of our natures. Schopenhauer, by contrast, takes aesthetic cognition to transcend (some of) the limitations of everyday cognition precisely because in it agents become the “pure, will-less subject of cognition” (WWR I 219). On the orthodox reading of his later philosophy, Nietzsche scorns Plato and Schopenhauer’s association of the value of art with its truthfulness. I challenge the orthodox reading and (...) argue that one strand of art’s value is its penetrative cognitive power. In contrast to Schopenhauer, Nietzsche understands this cognitive power to result from the embracing and exploitation of the affects in the artistic process rather than their extirpation. (shrink)