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. Por fim, os efeitos do fotoperíodo devem ser separados dos nutricionais, que também variam com a época do ano. -/- -/- REFERÊNCIAS BIBLIOGRÁFICAS -/- -/- BEARDEN, Henry Joe et al. Reproducción animal aplicada. México: Manual Moderno, 1982. -/- BROOKS, P. H.; COLE, D. J. A. The effect of the presence of a boar on the attainment of puberty in gilts. Reproduction, v. 23, n. 3, p. 435-440, 1970. -/- CARDOSO, Daniel; DE PAULA NOGUEIRA, Guilherme. Mecanismos neuroendócrinos envolvidos na puberdade de novilhas. Arquivos de Ciências Veterinárias e Zoologia da Unipar, v. 10, n. 1, 2007. -/- CHEMINEAU, P. et al. Induction and persistence of pituitary and ovarian activity in the out-of-season lactating dairy goat after a treatment combining a skeleton photoperiod, melatonin and the male effect. Reproduction, v. 78, n. 2, p. 497-504, 1986. -/- CLARKE, Iain J. et al. Kisspeptin and seasonality in sheep. Peptides, v. 30, n. 1, p. 154-163, 2009. -/- CORTEEL, J. M. Production, storage and insemination of goat semen. In: Management and Reproduction in Sheep and Goats Symposium, Madison, Wis. (USA), 1977. University of Wisconsin, 1977. -/- CUNNINGHAM, James. Tratado de fisiologia veterinária. Elsevier Health Sciences, 2011. -/- CUPPS, Perry T. (Ed.). Reproduction in domestic animals. Elsevier, 1991. -/- DUKES, Henry Hugh; SWENSON, Melvin J.; REECE, William O. Dukes fisiologia dos animais domésticos. Editora Guanabara Koogan, 1996. -/- DÝRMUNDSSON, Ó. R.; LEES, J. L. Effect of rams on the onset of breeding activity in Clun Forest ewe lambs. The Journal of Agricultural Science, v. 79, n. 2, p. 269-271, 1972. -/- EBLING, F. J. P.; FOSTER, D. L. Photoperiod requirements for puberty differ from those for the onset of the adult breeding season in female sheep. Reproduction, v. 84, n. 1, p. 283-293, 1988. -/- FIELDS, Michael J.; SAND, Robert S.; YELICH, Joel V. (Ed.). Factors affecting calf crop: Biotechnology of reproduction. 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)

This paper addresses the question of what the attitude of hope consists in. We argue that shortcomings in recent theories of hope have methodological roots in that they proceed with little regard for the rich body of literature on the emotions. Taking insights from work in the philosophy of emotions, we argue that hope involves a kind of normative perception. We then develop a strategy for determining the content of this perception, arguing that hope is a perception of practical reasons. (...) Our proposal stands in contrast with familiar views on which hope is fundamentally about the good. We conclude by considering the increasingly popular idea that some hopes are non-intentional and thus, by implication, non-perceptual. We reply by arguing that our perceptual theory plausibly generalizes to these instances of hope. (shrink)

This work addresses the autonomous organization of biological systems. It does so by considering the boundaries of biological systems, from individual cells to Home sapiens, in terms of the presence of Markov blankets under the active inference scheme—a corollary of the free energy principle. A Markov blanket defines the boundaries of a system in a statistical sense. Here we consider how a collective of Markov blankets can self-assemble into a global system that itself has a Markov blanket; thereby providing an (...) illustration of how autonomous systems can be understood as having layers of nested and self-sustaining boundaries. This allows us to show that: (i) any living system is a Markov blanketed system and (ii) the boundaries of such systems need not be co-extensive with the biophysical boundaries of a living organism. In other words, autonomous systems are hierarchically composed of Markov blankets of Markov blankets—all the way down to individual cells, all the way up to you and me, and all the way out to include elements of the local environment. (shrink)

This paper defends a theory of hope according to which hopes are composed of a desire and a belief that the object of the desire is possible. Although belief plus desire theories of hope are now widely rejected, this is due to important oversights. One is a failure to recognize the relation that hope-constituting desires and beliefs must stand in to constitute a hope. A second is an oversimplification of the explanatory power of hope-constituting desires. The final portion of the (...) paper uses an enhanced understanding of the psychology of hope to make progress on normative questions about hoping well. (shrink)

What is human understanding and why should we care about it? I propose a method of philosophical investigation called ‘function-first epistemology’ and use this method to investigate the nature and value of understanding-why. I argue that the concept of understanding-why serves the practical function of identifying good explainers, which is an important role in the general economy of our concepts. This hypothesis sheds light on a variety of issues in the epistemology of understanding including the role of explanation, the relationship (...) between understanding-why and knowledge, and the value of understanding-why. I conclude that understanding-why is valuable and yet knowledge plays more important roles in our epistemic life. (shrink)

The goal of this article is to present a first list of ethical concerns that may arise from research and personal use of virtual reality (VR) and related technology, and to offer concrete recommendations for minimizing those risks. Many of the recommendations call for focused research initiatives. In the first part of the article, we discuss the relevant evidence from psychology that motivates our concerns. In Section “Plasticity in the Human Mind,” we cover some of the main results suggesting that (...) one’s environment can influence one’s psychological states, as well as recent work on inducing illusions of embodiment. Then, in Section “Illusions of Embodiment and Their Lasting Effect,” we go on to discuss recent evidence indicating that immersion in VR can have psychological effects that last after leaving the virtual environment. In the second part of the article, we turn to the risks and recommendations. We begin, in Section “The Research Ethics of VR,” with the research ethics of VR, covering six main topics: the limits of experimental environments, informed consent, clinical risks, dual-use, online research, and a general point about the limitations of a code of conduct for research. Then, in Section “Risks for Individuals and Society,” we turn to the risks of VR for the general public, covering four main topics: long-term immersion, neglect of the social and physical environment, risky content, and privacy. We offer concrete recommendations for each of these 10 topics, summarized in Table 1. (shrink)

Imagination is necessary for scientific practice, yet there are no in vivo sociological studies on the ways that imagination is taught, thought of, or evaluated by scientists. This article begins to remedy this by presenting the results of a qualitative study performed on two systems biology laboratories. I found that the more advanced a participant was in their scientific career, the more they valued imagination. Further, positive attitudes toward imagination were primarily due to the perceived role of imagination in problem-solving. (...) But not all problem-solving episodes involved clear appeals to imagination, only maximally specific problems did. This pattern is explained by the presence of an implicit norm governing imagination use in the two labs: only use imagination on maximally specific problems, and only when all other available methods have failed. This norm was confirmed by the participants, and I argue that it has epistemological reasons in its favour. I also found that its strength varies inversely with career stage, such that more advanced scientists do (and should) occasionally bring their imaginations to bear on more general problems. A story about scientific pedagogy explains the trend away from (and back to) imagination over the course of a scientific career. Finally, some positive recommendations are given for a more imagination-friendly scientific pedagogy. (shrink)

Episodic memory (memories of the personal past) and prospecting the future (anticipating events) are often described as mental time travel (MTT). While most use this description metaphorically, we argue that episodic memory may allow for MTT in at least some robust sense. While episodic memory experiences may not allow us to literally travel through time, they do afford genuine awareness of past-perceived events. This is in contrast to an alternative view on which episodic memory experiences present past-perceived events as mere (...) intentional contents. Hence, episodic memory is a way of coming into experiential contact with, or being again aware of, what happened in the past. We argue that episodic memory experiences depend on a causal-informational link with the past events being remembered, and that, assuming direct realism about episodic memory experiences, this link suffices for genuine awareness. Since there is no such link in future prospection, a similar argument cannot be used to show that it also affords genuine awareness of future events. Constructivist views of memory might challenge the idea of memory as genuine awareness of remembered events. We explain how our view is consistent with both constructivist and anti-causalist conceptions of memory. There is still room for an interpretation of episodic memory as enabling genuine awareness of past events, even if it involves reconstruction. (shrink)

Many philosophers assume that, when making moral decisions under uncertainty, we should choose the option that has the greatest expected moral value, regardless of how risky it is. But their arguments for maximizing expected moral value do not support it over rival, risk-averse approaches. In this paper, I present a novel argument for maximizing expected value: when we think about larger series of decisions that each decision is a part of, all but the most risk-averse agents would prefer that we (...) consistently choose the option with the highest expected value. To the extent that what we choose on a given occasion should be guided by the entire series of choices we prefer, then on each occasion, we should choose the option with the highest expected moral value. (shrink)

This paper contains a critical examination of the prospects for analyses of knowledge that weaken the factivity condition such that knowledge implies approximate truth.

Epistemic decision theory produces arguments with both normative and mathematical premises. I begin by arguing that philosophers should care about whether the mathematical premises (1) are true, (2) are strong, and (3) admit simple proofs. I then discuss a theorem that Briggs and Pettigrew (2020) use as a premise in a novel accuracy-dominance argument for conditionalization. I argue that the theorem and its proof can be improved in a number of ways. First, I present a counterexample that shows that one (...) of the theorem’s claims is false. As a result of this, Briggs and Pettigrew’s argument for conditionalization is unsound. I go on to explore how a sound accuracy-dominance argument for conditionalization might be recovered. In the course of doing this, I prove two new theorems that correct and strengthen the result reported by Briggs and Pettigrew. I show how my results can be combined with various normative premises to produce sound arguments for conditionalization. I also show that my results can be used to support normative conclusions that are stronger than the one that Briggs and Pettigrew’s argument supports. Finally, I show that Briggs and Pettigrew’s proofs can be simplified considerably. (shrink)

The standard way to test alternative descriptive theories of moral judgment is by asking subjects to evaluate (amongst others) sacrificial dilemmas, where acting classifies as a utilitarian moral judgment and not acting classifies as a deontological moral judgment. Previous research uncovered many situational factors that alter subject’s moral judgments without affecting which type of action utilitarianism or deontology would recommend. This literature review provides a systematic analysis of the experimental literature on the influence of situational factors on moral judgments in (...) sacrificial dilemmas. It analyses 53 articles in detail and reports mean effect sizes, as well as operationalizations, for 36 situational factors that significantly influence moral judgment. Moreover, the review discusses how the impact of situational factors relates to a dual process theory of moral judgment. It supports the view that utilitarian judgments are driven by controlled cognitive processes and shows that the drivers of deontological judgments depend on valence. (shrink)

Conceptual limitations restrict our epistemic options. One cannot believe, disbelieve, or doubt what one cannot grasp. I show how, even granting an epistemic ought-implies-can principle, such restrictions might lead to epistemic dilemmas: situations where each of one’s options violates some epistemic requirement. An alternative reaction would be to take epistemic norms to be sensitive to one’s options in ways that ensure dilemmas never arise. I propose, on behalf of the dilemmist, that we treat puzzlement as a kind of epistemic residue, (...) roughly analogous with guilt, appropriate only when one has violated an epistemic requirement. Sometimes, in bumping up against the limits of one’s concepts, it is appropriate to be puzzled no matter what one believes. Puzzlement can thus play the same role in an epistemic dilemmist’s theory that guilt plays in the theories of many moral dilemmists. (shrink)

This paper outlines a new type of skepticism that is both compatible with fallibilism and supported by work in psychology. In particular, I will argue that we often cannot properly trust our ability to rationally evaluate reasons, arguments, and evidence (a fundamental knowledge-seeking faculty). We humans are just too cognitively impaired to achieve even fallible knowledge, at least for many beliefs.

The deaths of those on whom our practical identities rely generate a sense of disorientation or alienation from the world seemingly at odds with life being meaningful. In the terms put forth in Cheshire Calhoun’s recent account of meaningfulness in life, because their existence serves as a metaphysical presupposition of our practical identities, their deaths threaten to upend a background frame of agency against which much of our choice and deliberation takes place. Here I argue for a dual role for (...) grief in addressing this threat to life’s meaningfulness. Inasmuch as grief’s object is the loss of our relationship with the deceased as it was prior to their death, grief serves to alert us to the threat to our practical identities that their deaths pose to us and motivates us to defuse this threat by revising our practical identities to reflect the modification in our relationship necessitated by their deaths. Simultaneously, the emotional complexity and richness of grief episodes provides an abundance of normative evidence regarding our relationship with the deceased and our practical identities, evidence that can enable us to re-establish our practical identities and thereby recover a sense of our lives as meaningful. (shrink)

According to the received account of guilt in the philosophical literature, one cannot feel guilt unless one takes oneself to have done something morally wrong. But ordinary people feel guilt in many cases in which they do not take themselves to have done anything morally wrong. In this paper, I focus on one kind of guilt without perceived wrongdoing, guilt about being merely causally responsible for a bad state-of-affairs. I go on to present a novel account of guilt that explains (...) guilt about mere causal responsibility, according to which guilt represents part of the self as bound up with what is bad. (shrink)

It is often thought that metaphysical grounding underwrites a distinctive sort of metaphysical explanation. However, it would be a mistake to think that all metaphysical explanations are underwritten by metaphysical grounding. In service of this claim, I offer a novel kind of metaphysical explanation called metaphysical explanation by constraint, examples of which have been neglected in the literature. I argue that metaphysical explanations by constraint are not well understood as grounding explanations.

In a recent paper, Pettigrew reports a generalization of the celebrated accuracy-dominance theorem due to Predd et al., but Pettigrew’s proof is incorrect. I will explain the mistakes and provide a correct proof.

What form must a theory of epistemic injustice take in order to successfully illuminate the epistemic dimensions of struggles that are primarily political? How can such struggles be understood as involving collective struggles for epistemic recognition and self-determination that seek to improve practices of knowledge production and make lives more liveable? In this paper, I argue that currently dominant, Fricker-inspired approaches to theorizing epistemic wrongs and remedies make it difficult, if not impossible, to understand the epistemic dimensions of historic and (...) ongoing political struggles. Recent work in the theory of recognition— particularly the work of critical, feminist, and decolonial theorists—can help to identify and correct the shortcomings of these approaches. I offer a critical appraisal of recent conversation concerning epistemic injustice, focusing on three characteristics of Frickerian frameworks that obscure the epistemic dimensions of political struggles. I propose that a theory of epistemic injustice can better illuminate the epistemic dimensions of such struggles by acknowledging and centering the agency of victims in abusive epistemic relations, by conceptualizing the harms and wrongs of epistemic injustice relationally, and by explaining epistemic injustice as rooted in the oppressive and dysfunctional epistemic norms undergirding actual communities and institutions. (shrink)

Religious fictionalism is the theory that it is morally and intellectually legitimate to affirm religious sentences and to engage in public and private religious practices, without believing the content of religious claims. This article discusses the main features of fictionalism, contrasts hermeneutic, and revolutionary kinds of fictionalism and explores possible historical and recent examples of religious fictionalism. Such examples are found in recent theories of faith, pragmatic approaches to religion, and mystical traditions in religious theology.

In this paper I want to introduce and defend what I call the "subject mode account" of collective intentionality. I propose to understand collectives from joint attention dyads over small informal groups of various types to organizations, institutions and political entities such as nation states, in terms of their self-awareness. On the subject mode account, the self-consciousness of such collectives is constitutive for their being. More precisely, their self-representation as subjects of joint theoretical and practical positions towards the world – (...) rather than as objects of such positions – makes them what they are. Members of such collectives represent each other as co-subjects of such positions and thus represent the world from the point of view of the collective. (shrink)

This paper discusses Raimo Tuomela's we-mode account in his recent book "Social Ontology: Collective Intentionality and Group Agents" and develops the idea that mode should be thought of as representational. I argue that in any posture – intentional state or speech act – we do not merely represent a state of affairs as what we believe, or intend etc. – as the received view of 'propositional attitudes' has it –, but our position relative to that state of affairs and thus (...) ourselves. That is, we represent the subject through what I call "subject mode" and its position through what I call "position mode". I argue that the key to understanding collective intentionality is to understand how we represent others as co-subjects of positions rather than as their objects. This is shown on various levels of collective intentionality. On the non-conceptual level of joint attention we experience others as co-subjects who we attend with rather than to and who we are at least also disposed to act jointly with. On the conceptual level of the we-mode we represent others as co-subjects of positions of knowledge, intention, belief and shared values. Organizations and thus group agents in Tuomela's sense I propose to understand in terms of what I call "role mode", that is, in terms of the positions individuals and groups take as occupants of certain roles, for example, as committee members, or as chancellor of Germany. I try to show how this account, while very much in the spirit of Tuomela's, can avoid his fictionalism about group agents and some other problems of his account, while steering between the Scylla of excessive individualism and the Charybdis of extreme collectivism. (shrink)

We propose a fundamental challenge to the feasibility of moral progress: most extant theories of progress, we will argue, assume an unrealistic level of cognitive control people must have over their moral judgments for moral progress to occur. Moral progress depends at least in part on the possibility of individual people improving their moral cognition to eliminate the pernicious influence of various epistemically defective biases and other distorting factors. Since the degree of control people can exert over their moral cognition (...) tends to be significantly overestimated, the prospects of moral progress face a formidable problem, the force of which has thus far been underappreciated. In the paper, we will provide both conceptual and empirical arguments for this thesis, and explain its most important implications. (shrink)

Frege argued for the force-content distinction not only by appealing to the logical and fictional contexts which are most closely associated with the “Frege point", but also based on the fact that an affirmative answer to a yes-no question constitutes an assertion. Supposedly this is only intelligible if the question contains a forceless thought or proposition which an affirmative answer then asserts. Against this I argue that this fact more readily supports the view that questions operate on assertions and other (...) forceful acts themselves. Force is neither added to propositions as on the traditional view, nor is it cancelled as has recently been proposed. Rather higher-level acts such as questioning, but also e.g. conditionalizing, embed and present assertoric or directive acts that are forceful and committal, while suspending commitment to them. The Frege point confounds different varieties of force and the question whether something is merely presented for consideration with the question what is so presented. Force is representational: through assertoric and directive force indicators subjects non-conceptually present positions of theoretical or practical knowledge, while interrogative acts indicate positions of wondering which strive for such knowledge. (shrink)

Moral philosophy continues to be enriched by an ongoing empirical turn,mainly through contributions from neuroscience, biology, and psychology. Thusfar, cultural anthropology has largely been missing. A recent and rapidly growing‘ethical turn’ within cultural anthropologynow explicitly and systematically studiesmorality. This research report aims to introduce to an audience in moral philosophyseveral notable works within the ethical turn. It does so by critically discussing theethical turn’s contributions to four topics: the definition of morality, the nature ofmoral change and progress, the truth of (...) moral relativism, and attempts to debunkmorality. The ethical turn uncovers a richer picture of moral phenomena on theintersubjective level, one akin to a virtue theoretic focus on moral character, withstriking similarities of moral phenomena across cultures. Perennial debates are notsettled but the ethical turn strengthens moral philosophy’s empirical turn and itrewards serious attention from philosophers. (shrink)

Several anti-debunkers have argued that evolutionary explanations of our moral beliefs fail to meet a necessary condition on undermining defeat called modal security. They conclude that evolution, therefore, does not debunk our moral beliefs. This article shows that modal security is false if knowledge is virtuous achievement. New information can undermine a given belief without providing reason to doubt that that belief is sensitive or safe. This leads to a novel conception of undermining defeat, and it shows that successful debunking (...) of moral realism is possible. (shrink)

In this paper I propose three steps to overcome the force-content dichotomy and dispel the Frege point. First, we should ascribe content to force indicators. Through basic assertoric and directive force indicators such as intonation, word order and mood, a subject presents its position of theoretical or practical knowledge of a state of affairs as a fact, as something that is the case, or as a goal, as something to do. Force indicators do not operate on truth- or satisfaction evaluable (...) entities as on the traditional view, but complete and unify them. Second, higher-level acts such as interrogative, logical and fictional acts create higher-level unities that may suspend commitment to the assertions and directions they operate on. But they do not cancel their force, but transfer the meaning of force indicators into the new unities they create. For example, in the context of asking a theoretical or practical question, the assertoric or directive force indicator now presents the kind of knowledge the subject is seeking. Third, the Frege point conflates different varieties of force. We neither need Frege’s assertion sign, nor Hare’s neustic, nor Hanks’s cancellation sign, but only ordinary force indicators and interrogative, logical and fictional markers. Propositions are not forceless contents to which a subject commits by forceful acts, but forceful acts put forward by higher-level acts which may suspend commitment to them. (shrink)

What explains the outcomes of chance processes? We claim that their setups do. Chances, we think, mediate these explanations of outcome by setup but do not feature in them. Facts about chances do feature in explanations of a different kind: higher-order explanations, which explain how and why setups explain their outcomes. In this paper, we elucidate this 'mediator view' of chancy explanation and defend it from a series of objections. We then show how it changes the playing field in four (...) metaphysical disputes concerning chance. First, it makes it more plausible that even low chances can have explanatory power. Second, it undercuts a circularity objection against reductionist theories of chance. Third, it redirects the debate about a prominent argument against epistemic theories of chance. Finally, it sheds light on potential chancy explanations of the Universe's origin. (shrink)

The first part of this article makes the case that human cognition is an intergenerational project enabled by the inheritance and bequeathal of cognitive technology (Sects. 2–4). The final two sections of the article (Sects. 5 and 6) explore the normative significance of this claim. My case for the intergenerational claim draws results from multiple disciplines: philosophy (Sect. 2), cultural evolutionary approaches in cognitive science (Sect. 3), and developmental psychology and neuroscience (Sect. 4). In Sect. 5, I propose that cognitive (...) technology should be given to future generations in accordance with principles of pluralism and transparency. In the final main section of the article, Sect. 6, I apply these principles to topics such as the preservation of information, environmental offloading of cognition, and thinking itself. (shrink)

When philosophers discuss the possibility of machines making scientific discoveries, they typically focus on discoveries in physics, biology, chemistry and mathematics. Observing the rapid increase of computer-use in science, however, it becomes natural to ask whether there are any scientific domains out of reach for machine discovery. For example, could machines also make discoveries in qualitative social science? Is there something about humans that makes us uniquely suited to studying humans? Is there something about machines that would bar them from (...) such activity? A close look at the methodology of interpretive social science reveals several abilities necessary to make a social scientific discovery, and one capacity necessary to possess any of them is imagination. For machines to make discoveries in social science, therefore, they must possess imagination algorithms. (shrink)

John D. Norton is responsible for a number of influential views in contemporary philosophy of science. This paper will discuss two of them. The material theory of induction claims that inductive arguments are ultimately justified by their material features, not their formal features. Thus, while a deductive argument can be valid irrespective of the content of the propositions that make up the argument, an inductive argument about, say, apples, will be justified (or not) depending on facts about apples. The argument (...) view of thought experiments claims that thought experiments are arguments, and that they function epistemically however arguments do. These two views have generated a great deal of discussion, although there hasn’t been much written about their combination. I argue that despite some interesting harmonies, there is a serious tension between them. I consider several options for easing this tension, before suggesting a set of changes to the argument view that I take to be consistent with Norton’s fundamental philosophical commitments, and which retain what seems intuitively correct about the argument view. These changes require that we move away from a unitary epistemology of thought experiments and towards a more pluralist position. (shrink)

A recent surge of work on prediction-driven processing models--based on Bayesian inference and representation-heavy models--suggests that the material basis of conscious experience is inferentially secluded and neurocentrically brain bound. This paper develops an alternative account based on the free energy principle. It is argued that the free energy principle provides the right basic tools for understanding the anticipatory dynamics of the brain within a larger brain-body-environment dynamic, viewing the material basis of some conscious experiences as extensive--relational and thoroughly world-involving.

Cases of inexact observations have been used extensively in the recent literature on higher-order evidence and higher-order knowledge. I argue that the received understanding of inexact observations is mistaken. Although it is convenient to assume that such cases can be modeled statically, they should be analyzed as dynamic cases that involve change of knowledge. Consequently, the underlying logic should be dynamic epistemic logic, not its static counterpart. When reasoning about inexact knowledge, it is easy to confuse the initial situation, the (...) observation process, and the result of the observation; I analyze the three separately. This dynamic approach has far reaching implications: Williamson’s influential argument against the KK principle loses its force, and new insights can be gained regarding synchronic and diachronic introspection principles. (shrink)

While philosophers of mind have devoted abundant time and attention to questions of content and consciousness, philosophical questions about the nature and scope of mental action have been relatively neglected. Galen Strawson’s account of mental action, arguably the most well-known extant account, holds that cognitive mental action consists in triggering the delivery of content to one’s field of consciousness. However, Strawson fails to recognize several distinct types of mental action that might not reduce to triggering content delivery. In this paper, (...) we argue that meditation provides a useful model for understanding a wider range of types of mental action than heretofore recognized. Conclusions yielded by two distinct bodies of current psychological research on meditation and cognition, and meditation and introspection, buttress meditation’s suitability for this role. (shrink)

An intuitive objection to modal realism is that merely possible worlds and their inhabitants seem to be irrelevant to an analysis of modality. Kripke originally phrased the objection in terms of being concerned about one’s modal properties without being concerned about the properties one’s other-worldly counterparts have. The author assesses this objection in a variety of forms, and then provides his own formulation that does not beg the question against the modal realist. Finally, the author considers two potential answers to (...) the objection so understood and concludes that only one of them has a chance of succeeding. (shrink)

In recent years, multiple authors have voiced discontent with the theoretical and practical neglect of the concept of ability. This includes, but is not limited to, philosophers of disability who have long assailed the implausible accounts of ability utilized by most social and political philosophers. Historically, most philosophers took it for granted that the meaning of ability will come easily, or is even a given, when higher-order questions are addressed. The aim of this chapter is to animate discussions about ability (...) trouble, which is to say, to animate (i) concern over the lack of philosophical inquiry that takes the concept of ability seriously as a problem in its own right and to animate (ii) novel interest in and further research on the concept of ability—and, correlatively, disability. We first analyze a famous argument concerning moral status that exemplifies how treating the concept of ability as a mere matter of common sense can lead philosophical inquiry awry. We then turn to the role of the concept of ability in an account that does, at least prima facie, take the concept seriously: Sen and Nussbaum’s capabilities approach. While better than common-sense approaches, we draw a cautionary tale, suggesting that even there the concept is simplified in theoretically and practically problematic ways. We conclude with a number of open questions offered in the hope of inspiring future non-ideal research on the topic. (shrink)

Van Fraassen’s (1989) infamous best of a bad lot objection is widely taken to be the most serious problem that afflicts theories of inference to the best explanation (IBE), for it alleges to show that we should not accept the conclusion of any case of such reasoning as it actually proceeds. Moreover, this is supposed to be the case irrespective of the details of the particular criteria used to select best explanations. The best of a bad lot objection is predicated (...) on, and really only requires, the idea that in any real case of IBE where one hypothesis is favored as best over those with which it competes, it is always the case that it is more likely that the true explanation is to be found in the set of unformulated and unconsidered logical alternatives to the set of actually considered hypotheses. On this basis, Van Fraassen believes that accepting the conclusion of IBEs so understood is irrational and this is simply because such inferences are supposedly not probative. In this paper the best of a bad lot objection will be addressed and it will be shown that Van Fraassen’s notorious criticism of IBE depends on a problematic conflation of two notions of rationality and thus that his criticism of IBE involves a damning equivocation. In essence, he conflates ideal standards of rationality with epistemic standards of rationality and, in so doing, makes it appear to be the case that we should not accept the conclusions of IBEs. But, when we disambiguate the concepts of rationality at work in the argument Van Fraassen’s conclusion simply does not follow. (shrink)

Drawing on a rich pragmatist tradition, this book offers an account of the different kinds of ‘oughts’, or varieties of normativity, that we are subject to contends that there is no conflict between normativity and the world as science describes it. The authors argue that normative claims aim to evaluate, to urge us to do or not do something, and to tell us how a state of affairs ought to be. These claims articulate forms of action-guidance that are different in (...) kind from descriptive claims, with a wholly distinct practical and expressive character. This account suggests that there are no normative facts, and so nothing that needs any troublesome shoehorning into a scientific account of the world. This work explains that nevertheless, normative claims are constrained by the world, and answerable to reason and argumentation, in a way that makes them truth-apt and objective. (shrink)

In this paper I criticize theory-biased and overly individualist approaches to understanding others and introduce the PAIR account of joint attention as a pragmatic, affectively charged intentional relation. I argue that this relation obtains in virtue of intentional contents in the minds of the co-attenders, and – against the received understanding of intentional states as propositional attitudes – that we should recognize what I call “subject mode” and “position mode” intentional content. Based on findings from developmental psychology, I propose that (...) subject mode content represents the co-attenders as co-subjects, who are like them and who are at least disposed to act jointly with them. I conclude by arguing that in joint attention we experience and understand affective, actional and perceptual relations at a non-conceptual level prior to the differentiation of mind and body. (shrink)

This article argues that manipulation is negligent influence. Manipulation is negligent in the sense that manipulators do not chose their method of influence because for its potential to reveal reasons to their victims. Thus, manipulation is a lack of care, or negligence, exclusively understood exclusively in terms of how one influences. That makes the proposed account superior to the most influential alternative, which analyses manipulation disjunctively as violation of several distinct types of norms. The implication is a paradigm shift in (...) understanding manipulation in terms of what manipulators intend to do toward a focus on what they fail to do or intend. (shrink)

I develop a psychological account for how it is that we use imagination to metaphysically modalize, i.e., to reach conclusions about metaphysical modality. Specifically, I argue that Nichols and Stich’s (2003) cognitive theory of imagination can be extended to metaphysical modalizing. I then use the extension to explicate philosophical disagreements about whether a scenario is metaphysically possible. Thereafter, I address Nichols’ (2006) objection that psychologizing imagination makes it clear that imagination is unreliable when used to metaphysically modalize. The end result (...) is a naturalistic account for how imagination enables us to metaphysically modalize. (shrink)

Problematic perceptions about race damage our society. These attitudes can seem impossible to overcome, but philosophers Dr Jennifer Mensch, at Western Sydney University in Australia, and Dr Michael Olson, at Marquette University in the US, beg to differ. They are compiling a collection of 18th-century philosophical and scientific texts that helped shape the way people saw race across the Western world, and were used to justify colonisation. They believe that by exposing these historical roots of racism, opportunities to improve (...) societal attitudes to race will become easier to identify. -/- This article was produced by Futurum Careers, a free online resource and magazine aimed at encouraging 14-19-year-olds worldwide to pursue careers in science, technology, engineering, maths and medicine (STEM), and social sciences, humanities and the arts for people and the economy (SHAPE). (shrink)

Awareness and concern about climate change are widespread. But rates of pro-environmental behaviour are low. This is partly due to the way in which pro-environmental behaviour is framed—as a sacrifice or burden that individuals bear for the planet and future generations. This framing elicits well-known cognitive biases, discouraging what we should be encouraging. We should abandon the self-sacrifice framing, and instead frame pro-environmental behaviour as intrinsically desirable. There is a large body of evidence that, around the world, people who are (...) living more environmentally lifestyles are happier than those not doing so. This is the message we should be spreading. (shrink)

Amid the wide variety of interpretations of quantum mechanics, the notion of a fully coherent ontological interpretation has seen a promising evolution over the last few decades. Despite this progress, however, the old dualistic categorical constraints of subjectivity and objectivity, correlate with the metrically restricted definition of local and global, have remained largely in place – a reflection of the broader, persistent inheritance of these comfortable strictures throughout the evolution of modern science. If one traces this inheritance back to its (...) ancient roots in Plato and Aristotle, it is clear that the coherence, scientific utility, and historical durability of the various natural philosophies that followed have been directly proportional to their commitment, tacit or explicit, to object-oriented realism. As Simondon might put it, it is a commitment to the primacy of individuated substance over the process of individuation. For Whitehead, it is the misplaced assimilation of becoming to being, of potentiality to actuality. Quantum mechanics has challenged this commitment with a combined breadth and depth of force that far exceeds any other theory in the history of science. The theory’s objectively demonstrable empirical application is manifest only by way of a fundamentally subjective, context-dependent mechanism of measurement. More compelling still, actual system states are always actualizations of locally contextualized yet globally conditioned potential system states, such that “globally objective” reality is no longer merely the object of local measurement, but also its product. Thus, any coherent, ontological interpretation of quantum theory must include a conceptual framework by which objectivity and subjectivity, actuality and potentiality, global and local, being and becoming, individuated fact and process of individuation, are no longer understood as merely epistemic, mutually exclusive category pairs descriptive of an already extant, closed reality – but rather as mutually implicative ontological categories explicative of an ontogenetic, open reality-in-process. (shrink)

I offer new arguments for an unorthodox reading of J. L. Mackie’s Ethics: Inventing Right and Wrong, one on which Mackie does not think all substantive moral claims are false, but allows that a proper subset of them are true. Further, those that are true should be understood in terms of a “hybrid theory”. The proposed reading is one on which Mackie is a conceptual pruner, arguing that we should prune away error-ridden moral claims but hold onto those already free (...) of error. This reading is very different from the standard ones found in the literature. I build on recent work by Moberger and argue that this reading is better corroborated by close attention to the way in which Mackie argues at length that terms like “good” and “ought” are systematically context-sensitive, as well as by considerable additional textual evidence. This reading, however, faces an important challenge—to explain in what sense, if any, morality retains its “normativity” on the proposed reading. I argue that this challenge can be met, at least given some of Mackie’s further assumptions about the nature of rationality. (shrink)

We thank all the thoughtful authors for their insightful comments. In this response, we try to address some of themes that emerged from the commentaries. We leave aside some of those comments that...

This paper will aim to accomplish two things to show Luhmann’s and Hegel’s support of language and communication as dependent on culture, but also their differences with respect to how culture is formed in conjunction with the environment. This paper will firstly show how Hegel distinguishes between the imagination and reason in a different manner from Luhmann, as Hegel considers them logically connected while Luhmann considers them as coextensive. Secondly, this paper will show how reason and imagination create culture through (...) the environment via dialectical idealism in Hegel and a poly-contextural constructivist approach in Luhmann. (shrink)

Drawing upon empirical studies of racial discrimination dating back to the 1940’s, the Movement for Black Lives platform calls for the abolition of capital punishment. Our purpose here is to defend the Movement’s call for death penalty abolition in terms congruent with its claim that the death penalty in the U.S. is a “racist practice” that “devalues Black lives.” We first sketch the jurisprudential history of race and capital punishment in the U.S., wherein courts have occasionally expressed worries about racial (...) injustice but have usually taken such evidence to warrant reform but not outright abolition. We argue that the racial discrimination at issue flows in significant part from implicit biases concerning race, criminality, and violence, which do not fit comfortably within the picture of racial bias advanced by the courts. The case for abolition, we contend, rests on Black Americans as a class (not merely those who interact with the criminal justice system as capital defendants or as murder victims) being subject to such bias and thereby not being accorded equal status under the law. (shrink)

In this paper we examine the role the Dutch gymnasium continues to play in the institutional maintenance of educational inequality. To that end we examine the relational and spatial features of state-sponsored elite education in the Dutch system: the unique identity the gymnasium seeks to cultivate; its value to its consumers; its geographic significance; and its market position amidst a growing array of other selective forms of schooling. We argue that there is a strong correlation between a higher social class (...) background and the concern to transmit one’s cultural habitus. We further speculate on the moral implications of state-sponsored elite education, both as it concerns the specific role of the gymnasium in the reproduction of social inequality as well as the curious tendency among its supporters to rationalise the necessity of its existence. (shrink)

Commentators disagree about the extent to which Kant’s ethics is compatible with consequentialism. A question that has not yet been asked is whether Kant had a view of his own regarding the fundamental difference between his ethical theory and a broadly consequentialist one. In this paper I argue that Kant does have such a view. I illustrate this by discussing his response to a well-known objection to his moral theory, namely that Kant offers an implicitly consequentialist theory of moral appraisal. (...) This objection was most famously raised by Mill and Schopenhauer, but also during Kant’s time by Pistorius and Tittel. I show that Kant’s response to this objection in the second Critique illustrates that he sees the fundamental difference between his moral theory and a broadly consequentialist one to be one that concerns methodology. (shrink)