TRANSPORTE DE GAMETAS, FERTILIZAÇÃO E SEGMENTAÇÃO -/- • _____OBJETIVO -/- O entendimento do desenvolvimento embrionário nos estágios iniciais, desde a deposição dos espermatozoides na fêmea, passando pela fertilização deste no ovócito e na formação do zigoto, é de suma importância para diferenciar especialistas em reprodução e manejo reprodutivo no mercado de trabalho e, também, durante a vida acadêmica. Compreender os processos que levam à formação do zigoto na fêmea é essencial para avaliar a capacidade reprodutiva dos animais e, mediante técnicas, (...) avaliar o trato reprodutivo da fêmea e o desenvolvimento do embrião até a formação do feto e, por fim, em um novo animal sadio na propriedade. Com esse trabalho, o estudante de veterinária ou zootecnia, que deseja se aprofundar na fisiologia da reprodução animal, identificará os mecanismos que são envolvidos no transporte dos gametas, bem como os processos que estes últimos devem completar para alcançar a fertilização e para desencadear as divisões iniciais do embrião. -/- • _____INTRODUÇÃO -/- A fertilização ou fecundação é o processo pelo qual os gametas masculino (espermatozoide) e feminino (ovócito) se fundem para gerar um novo indivíduo. Seu êxito depende da culminação adequada dos diferentes processos que devem sofrer os gametas durante sua maduração e percurso; do transporte oportuno destes no trato reprodutivo da fêmea, assim como de uma série de adaptações dos órgãos genitais internos da mãe. A segmentação refere-se às primeiras divisões celulares do embrião. -/- • _____TRANSPORTE DO OVÓCITO -/- O ovócito que é liberado na ovulação, e que se encontra coberto pelas células do cumulus (figura 1), é capturado pela fímbria do infundíbulo ao aderir aos cílios. Esse processo é altamente eficaz, inclusive em espécies onde os ovários possuem várias formações globosas, por exemplo nas porcas, onde os ovidutos capturam entre 95 e 100% dos ovócitos que são ovulados. As contrações das camadas musculares do oviduto e o movimento intenso dos cílios da mucosa faz com que as secreções fluam em direção ao útero, transportando assim o complexo cumulus-ovócito. Esse transporte é relativamente rápido até alcançar a junção da ampola com o istmo (que é considerado o local de fertilização do espermatozoide e ovócito) a partir do qual se torna lento. Devido a fêmea estar em estro, o processo está sob controle endócrino, isto é, controle hormonal através do estradiol. Nas fêmeas domésticas, ao contrário das mulheres, o transporte ao longo do oviduto é extremamente eficiente, pois os embriões passam para o útero sem dificuldade, de modo que gestações ectópicas (tubárias ou em cavidade) são quase inexistentes. A égua, frequentemente, retém por muito tempo os ovócitos não fertilizados no oviduto, provavelmente devido a não secreção de substâncias (como a prostaglandina E) que poderiam favorecer sua passagem, como se propõe que aconteça com os embriões. A figura 2 apresenta um ovócito com suas respectivas estruturas. Figura 1: ovócitos de uma vaca madurados in vitro. Nota-se as células do cumulus que os recobre. -/- Figura 2: estruturas do ovócito de uma ovelha que se encontra na etapa de ovócito secundário, depois da ovulação. Elaborado pelo autor. • _____TRANSPORTE ESPERMÁTICO -/- Para que os espermatozoides sejam capazes de fertilizar o ovócito, deverão sofrer uma série de mudanças bioquímicas e morfológicas ao longo de sua passagem pelo aparelho reprodutor tanto masculino como feminino. Uma vez produzidos na parede do túbulo seminífero, os espermatozoides são liberados em direção ao lúmen tubular e transportados passivamente para uma estrutura ramificada conhecida como rede testicular (rete testis). Dessa rede são conduzidos em direção ao epidídimo passando através de 10 a 20 ductos eferentes localizados no polo superior do testículo. O epidídimo é dividido em três seções denominadas cabeça, corpo e cauda; é constituído por um só ducto longo e tortuoso que continua com o canal deferente. Ao final desemboca nas ampolas seminais, no ducto ejaculatório e na uretra. As funções do epidídimo são as de maduração, transporte e armazenamento dos espermatozoides. O transporte através do epidídimo é lento, aproximadamente de 10 dias em touros, e segue sendo passivo. Os espermatozoides tomados da cabeça do epidídimo são ainda imaturos e incapazes de fertilizar, enquanto os armazenados na cauda são completamente maduros. Durante o trânsito pelo epidídimo os espermatozoides adquirem motilidade e o potencial para fertilizar, o acrossomo é remodelado e a gota citoplasmática migra para o flagelo e é liberada. Quando um macho ejacula com muita frequência, é possível observar espermatozoides com gota citoplasmática no sêmen, já que não há tempo suficiente para que completem sua maduração. Os espermatozoides são expulsados fora do organismo durante a cópula, na masturbação ou em emissões espontâneas. Na ejaculação, os espermatozoides que se encontram suspensos nos fluidos do testículo e do epidídimo, misturam-se ao chegar na uretra com as secreções das glândulas acessórias para formar o sêmen. Essas secreções denominadas plasma seminal, proporcionam substâncias para manter o metabolismo energético das células espermáticas, e integram suas membranas elementos que impedem uma capacitação prematura. Durante a cópula, o sêmen é depositado na vagina ou no útero, variando entre as espécies (tabela 1). Na monta natural, geralmente, o serviço ocorre no momento propício, já que está definido pela fase do ciclo estral em que a fêmea é receptiva ao macho. No entanto, na inseminação artificial, é o macho que deverá determinar o momento ideal, e para isso é importante considerar a vida média dos gametas, ao qual é muito curta no caso dos ovócitos (tabela 1). -/- Tabela 1: local de depósito do sêmen, volume da ejaculação e vida média dos gametas. Espécie Local de deposição Volume (ml) Velocidade de ejaculação Vida média do ovócito Vida média do espermatozoide Bovinos Intravaginal 2 1 – 3 seg 8 h 30 – 48 h Caninos Intravaginal 2 – 30 (10 média) 6 – 45 min 48 – 72 h 9 – 11 d Equinos Intrauterina 50 – 200 20 – 60 seg 6 – 8 h 72 – 120 h Humanos Intravaginal 3 - - 5 – 6 d Ovinos Intravaginal 1 1 – 2 seg 16 – 24 h 30 – 48 h Suínos Intrauterina 200 – 400 5 – 20 min 8 – 10 h 24 – 48 h Onde d = dias; h = horas. A vida fértil do ovócito é muito curta, portanto, o momento do serviço é de grande importância para obter altos índices de fertilização. -/- Independentemente do local em que os espermatozoides sejam depositados no aparelho reprodutor feminino, serão expostos às secreções genitais e sofrem uma série de mudanças em seu trajeto até o local de fertilização antes de penetrar no ovócito. Nas espécies em que o sêmen é depositado na parte cranial da vagina, uma parte do mesmo penetra através da cérvix, enquanto outra parte é eliminada do aparelho genital da fêmea, em pouco tempo, através do fluxo retrógrado. O meio vaginal não é adequado e imobiliza os espermatozoides em pouco tempo, pelo qual deverão entrar no útero onde o ambiente é mais propício. O transporte espermático na fêmea é o resultado da alta contratilidade, do movimento ciliar e o fluido do aparelho genital durante o estro, ao qual está sob controle endócrino e do sistema nervoso. Esse transporte é favorecido pelas características especiais do muco estral, cujas moléculas formam uma espécie de canais que facilitam a passagem dos espermatozoides. Pelo contrário, durante a fase lútea seu transporte é dificultado. Além do meio vaginal, a cérvix também atua como barreira natural para limitar a passagem dos espermatozoides, diminuindo assim a possibilidade de polispermia. Funciona, também, como um filtro que seleciona os espermatozoides aptos dos que não o são, uma vez que somente os primeiros possuem uma motilidade vigorosa que lhes permite passar pelo muco altamente hidratado. Na vaca a cérvix é considerada como um reservatório espermático. Quando atravessam a cérvix, os espermatozoides seguem sua deslocação tanto por movimento próprio como pelas contrações uterinas e tubárias. Nas espécies em que o local de depósito do sêmen do macho na fêmea é intrauterino, como equinos, a principal barreira que os espermatozoides enfrentam é a união ou junção útero-tubárica. A união entre o útero e o oviduto (istmo do oviduto) serve como reservatório funcional dos espermatozoides nas espécies domésticas. Poucos minutos depois da cópula, é possível encontrar alguns espermatozoides no oviduto, que é conhecido como fase de transporte rápido. No entanto, esses espermato-zoides não são os que participam do processo de fertilização e podem apresentar certas anormalidades. Existe um segundo tipo de transporte denominado fase sustentada, a qual consiste na migração prolongada dos espermatozoides em direção as partes mais craniais do aparelho genital feminino, que conduzem à colonização do reservatório funcional e na liberação gradual dos espermatozoides dos reservatórios espermáticos, incluindo este último. O reservatório do istmo fornece aos espermatozoides um ambiente propício, protegendo-os contra a fagocitose, prolongando assim a sua viabilidade. Aqui os esper-matozoides permanecem aderidos a superfície das células ciliadas do epitélio até a finalização de sua capacitação, depois da qual são liberados quando alteram seu padrão de motilidade flagelada, fenômeno conhecido como hipermotilidade, e migram em ondas em direção ao local da fertilização. Dos milhões de espermatozoides ejaculados, somente alguns milhares alcançarão o istmo do oviduto e um número sumamente pequeno será encontrado nas imediações do ovócito no momento da fertilização. -/- • _____CAPACITAÇÃO ESPERMÁTICA E REAÇÃO ACROSSÔMICA -/- A capacitação é um processo gradual e essencial para a fertilização. Os espermato-zoides devem passar por um dado tempo de “incubação” no aparelho genital da fêmea e sofrer uma série de mudanças antes de serem capazes de fecundar o ovócito. A capacita-ção dos espermatozoides começa quando eles entram em contato com as secreções do aparelho genital da fêmea e termina no istmo do oviduto. Durante esse percurso a superfície da cabeça do espermatozoide se modifica já que algumas moléculas como o colesterol são removidas da membrana plasmática, aumentando sua fluidez e alterando suas propriedades bioquímicas. Entre outras coisas, essa reorganização dos lipídios facilita a entrada de cálcio extracelular pelos canais iônicos e ocasiona a desestabilização da membrana, tornando-a mais fusogênica. Também são eliminados outros fatores (conhecidos genericamente como fatores descapacitantes) que expõem receptores membranais indispensáveis para a realização da união entre o espermatozoide e o ovócito durante a fertilização. Os espermatozoides capacitados apresentam um padrão de hipermotilidade e uma maior atividade metabólica, características que devem obter para que sejam capazes de penetrar as camadas do ovócito. A capacitação é necessária para que ocorra a reação acrossômica. A reação acrossomal ou acrossômica (RA) é um fenômeno de exocitose que é desencadeada pela ligação entre as proteínas e receptores localizados na membrana do espermatozoide e a zona pelúcida do ovócito (figura 3). Envolve a fusão da membrana plasmática do espermatozoide com a membrana externa de seu acrossomo; formando, assim, pequenas vesículas, cujo conteúdo de enzimas hidrolíticas, como a hialuronidase e a acrosina, é liberado em direção ao seu exterior, facilitando a penetração da zona pelúcida. A adesão do espermatozoide à zona pelúcida é específica da espécie e depende de glicoproteínas presentes na membrana dos ovócitos maduros; a cabeça do espermatozoide se une com essas glicoproteínas mediante receptores específicos e atravessam em direção oblíqua a zona pelúcida até chegar ao espaço perivitelino. Nos mamíferos, particularmente em roedores e nos humanos, algumas dessas glicoproteínas são conhecidas como ZP1, ZP2 e ZP3. Pensa-se que a união da membrana espermática a esta última é o que desencadeia a reação acrossomal. Posteriormente, as vilosidades do ovócito entram em contato com o espermatozoide e a membrana presente na secreção equatorial da cabeça do espermatozoide, que tem proteínas fusogênicas específicas, une-se a membrana plasmática do ovócito, fusionando-se e permitindo a entrada do núcleo espermático ao citoplasma (figura 4). A capacitação dos espermatozoides é fundamental para o êxito da fertilização, uma vez que apenas os aptos estarão perfeitos e íntegros para que a união e percepção das glicoproteínas presentes nos mesmos possam ocorrer de forma ideal para a penetração deste no ovócito, fertilizá-lo e formar um zigoto. Figura 3: estrutura do espermatozoide. Nota: a membrana é acrossomal e não acrossonal. Elaborado pelo autor. -/- Figura 4: eventos que ocorrem durante a fertilização. A – depois de passar através das células do cumulus, o espermatozoide entra em contato com a zona pelúcida, onde receptores da membrana plasmática reconhecem as proteínas da zona pelúcida; B – é desencadeada, então, a reação acrossomal; C – para que o espermatozoide penetre na zona pelúcida; D – ao atravessar a zona pelúcida e entrar no espaço perivitelino, a cabeça do espermatozoide entra em contato com a membrana vitelina; ambas membranas se fusionam graças ao reconhecimento de proteínas fusogênicas que estão no segmento equatorial. E – ocorre, então, que o núcleo do espermatozoide penetra no citoplasma do ovócito; uma das consequências da fusão da membrana com a cabeça do espermatozoide é a reação cortical, em que os grânulos corticais do ovócito liberam seu conteúdo em direção ao espaço perivitelino, o que resulta na alteração da estrutura da zona pelúcida e da membrana vitelina para bloquear a polispermia. Elaborado pelo autor. • _____CONSEQUÊNCIAS DA PENETRAÇÃO -/- Bloqueio da polispermia -/- A fusão das membranas dos gametas durante a penetração permite a entrada da fosfolipase C zeta (PLCζ) – fator solúvel que provém do espermatozoide – que desencadeia liberação e oscilações de Ca2+ no retículo endoplasmático. Isso, por sua vez, provoca a migração e fusão dos grânulos corticais, com a consequente liberação de enzimas, que mudam tanto a estrutura da zona pelúcida (por exemplo a inativação de ZP3), como a da membrana vitelina. Desse modo, impede-se que outros espermatozoides as penetrem, evitando assim a polispermia (figura 5). -/- Figura 5: os grânulos corticais que encontram-se na periferia do citoplasma, debaixo da superfície da membrana do ovócito, migram e fusionam-se sobre a mesma, liberando seu conteúdo no espaço perivitelino imediatamente depois da penetração do espermatozoide. A – como conse-quência, tanto a membrana vitelina como a zona pelúcida são modificadas, impedindo a entrada de mais espermatozoides, o que evita a polispermia. B – o ovócito retoma, então, sua segunda divisão meiótica, que ocasiona a expulsão do segundo corpúsculo polar, e na formação dos pronúcleos feminino e masculino. C – continuando, os pronúcleos migram, suas membranas se dissolvem e os cromossomos de ambos se condensam e se unem. Completa-se, assim, a singamia e forma-se, então, o zigoto. Elaborado pelo autor baseado nos livros de embriologia e fisiologia da reprodução conforme vida bibliografia. -/- Ativação do ovócito e formação de pronúcleos -/- Na maioria das fêmeas domésticas, com exceção da cadela, o ovócito encontra-se suspenso na metáfase II da segunda meiose no momento da ovulação. A entrada da PLCζ do espermatozoide no citoplasma do ovócito, e a consequente liberação de Ca2+, faz com que o ovócito se ative, terminando a segunda divisão meiótica e expulse o segundo corpo polar. Posteriormente, o material nuclear do ovócito se reorganiza para formar o pronú-cleo feminino. Entretanto, a membrana nuclear do espermatozoide se dissolve, a cromatina descondensa-se, as protaminas são substituídas por histonas, e se forma uma nova membrana nuclear, dando lugar ao pronúcleo masculino. -/- Singamia -/- Uma vez que os pronúcleos feminino e masculino são formados, migram para o centro do ovócito, aproximam-se, suas membranas se dispersam e os cromossomos paternos e maternos se associam, com o qual recupera a condição diploide e dá origem ao zigoto (figura 5). -/- • _____DESENVOLVIMENTO EMBRIONÁRIO -/- Poucas horas após a fertilização ocorre a primeira divisão do zigoto em duas, depois em 4, 8, 16 e 32 células, denominadas blastômeros. Essas divisões mitóticas são conhecidas como divisões de segmentação ou clivagem (figura 6), uma vez que são realizadas sem aumento do citoplasma, de modo que com cada divisão os blastômeros se tornam menores. A partir das 16 células o embrião se chama mórula, e é visto como uma massa celular compacta. A compactação deve-se a informação de proteínas de ligação entre os blastômeros. O embrião acumula líquido em seu interior, formando uma cavidade denominada blastocele. Esse processo é conhecido como blastulação; o embrião, assim, passa a ser chamado de blastocisto. Nessa etapa é possível diferenciar duas populações de células embrionárias: a massa celular interna, embrioblasto ou botão embrionário (que dará origem ao embrião), e a massa celular externa, células superficiais ou trofoblasto, do qual se originam a maioria das membranas fetais. Ao continuar a multiplicação das células e a acumulação de líquido, o blastocisto aumenta de tamanho, convertendo-se em blastocisto expandido. A zona pelúcida torna-se mais fina e, finalmente, o embrião eclode; isto é, o embrião é liberado da zona pelúcida. -/- • _____FERTILIZAÇÕES ATÍPICAS -/- Polispermia -/- É a penetração de dois ou mais espermatozoides no óvulo. Esta condição é letal nos mamíferos, já que o número cromossômico desse zigoto é maior que 2n, o envelheci-mento do ovócito da porca, como consequência do serviço tardio, favorece a apresentação da polispermia, por isso, é comum ver números de nascimentos de média de 10 a 12 leitões por parição nessa espécie. Nas aves, no entanto, a penetração de mais de um espermatozoide é normal, embora apenas um pronúcleo masculino se formará, fundindo-se com o feminino. -/- Figura 6: etapas do processo de segmentação/clivagem. Fonte: aula de reprodução da professora Domenica Palomaris, UFT. -/- Ginogênese -/- É o desenvolvimento de um embrião a partir de um óvulo normal fecundado por um espermatozoide, mas sem a fusão dos cromossomos masculinos com os da fêmea. A função do espermatozoide, nesse caso, é a de ativação do ovócito para que este inicie seu desenvolvimento, mas não há fusão com o núcleo do espermatozoide. Ocorre em plantas, em nematódeos e em algumas espécies de peixes, por exemplo a Poecilia formosa, espécie em que os ovócitos das fêmeas são ativados por machos de outra espécie relacio-nada. -/- Partenogênese -/- Consiste no desenvolvimento do embrião sem a participação do espermatozoide. Ocorre em alguns insetos, o zangão, por exemplo, é partenogenético. Também pode apresentar-se em perus, cujos embriões são machos e, geralmente, morrem antes da eclosão. -/- • _____GÊMEOS -/- Existem dois tipos de gêmeos: idênticos ou monozigóticos e os não idênticos ou dizigóticos. -/- Idênticos ou monozigóticos -/- Originam-se do mesmo zigoto, sendo assim, possuem o mesmo genótipo e um fenótipo similar e, portanto, são do mesmo sexo. Em laboratório é possível gerá-los ao seccionar uma mórula em duas ou mais partes, por meio de um micromanipulador. Uma vez que possuem o mesmo genótipo, os produtos resultantes são clones. -/- Não idênticos ou dizigóticos -/- Provêm da fertilização de dois óvulos distintos por espermatozoides diferentes. Possuem, portanto, genótipos e fenótipos diferentes, e podem ser de sexo diferente. -/- REFERÊNCIAS BIBLIOGRÁFICAS -/- ALBERTS, Bruce et al. Biologia molecular da célula. Artmed Editora, 2010. AUSTIN, Colin Russell; SHORT, Roger Valentine. Reproduction in Mammals, Book I: Germ Cells and Fertilization. 1982. BEARDEN, Henry Joe et al. Reproducción animal aplicada. México: Manual Moderno, 1982. BOSCH, P.; WRIGHT JR, R. W. The oviductal sperm reservoir in domestic mammals. Archivos de medicina veterinaria, v. 37, n. 2, p. 95-105, 2005. CAPALLEJAS, Roberto Brito; RODRÍGUEZ, Lourdes Tagle. Fisiología de la reproducción animal: con elementos de biotecnología. Editorial Félix Varela, 2010. CROXATTO, Horacio B. Physiology of gamete and embryo transport through the fallopian tube. Reproductive biomedicine online, v. 4, n. 2, p. 160-169, 2002. CUPPS, Perry T. (Ed.). Reproduction in domestic animals. Elsevier, 1991. DIEDRICH, Smidt et al. Endocrinología y Fisiología de la Reproducción de los Animales Zootécnicos. 1972. DUKES, Henry Hugh; SWENSON, Melvin J.; REECE, William O. Dukes fisiologia dos animais domésticos. Editora Guanabara Koogan, 1996. FERREIRA, A. de M. Reprodução da fêmea bovina: fisiologia aplicada e problemas mais comuns (causas e tratamentos). Juiz de Fora: Minas Gerais–Brasil, p. 422, 2010. HAFEZ, Elsayed Saad Eldin; HAFEZ, Bahaa. Reprodução animal. São Paulo: Manole, 2004. HUNTER, Ronald Henry Fraser. The Fallopian tubes in domestic mammals: how vital is their physiological activity?. Reproduction Nutrition Development, v. 45, n. 3, p. 281-290, 2005. HUNTER, R. H. F.; RODRIGUEZ‐MARTINEZ, H. Capacitation of mammalian spermatozoa in vivo, with a specific focus on events in the Fallopian tubes. Molecular Reproduction and Development: Incorporating Gamete Research, v. 67, n. 2, p. 243-250, 2004. GALINA, Carlos; VALENCIA, Javier. Reproducción de los animales domésticos. 2006. HOPPER, Richard M. (Ed.). Bovine reproduction. John Wiley & Sons, 2014. HYTTEL, Poul; SINOWATZ, Fred; VEJLSTED, Morten. Embriologia veterinária. Elsevier Brasil, 2012. KÖLLE, Sabine; REESE, Sven; KUMMER, Wolfgang. New aspects of gamete transport, fertilization, and embryonic development in the oviduct gained by means of live cell imaging. Theriogenology, v. 73, n. 6, p. 786-795, 2010. MCKINNON, Angus O. et al. (Ed.). Equine reproduction. John Wiley & Sons, 2011. OLIVERA, Martha et al. El espermatozoide, desde la eyaculación hasta la fertilización. Revista Colombiana de Ciencias Pecuarias, v. 19, n. 4, p. 426-436, 2006. PLANT, Tony M.; ZELEZNIK, Anthony J. (Ed.). Knobil and Neill's physiology of reproduction. New York: Academic Press, 2014. RODRIGUEZ-MARTINEZ, Heriberto. Role of the oviduct in sperm capacitation. Theriogenology, v. 68, p. S138-S146, 2007. SAAVEDRA LEOS, María Dolores. Estudio de la composición de los gránulos corticales y del oolema de ovocitos porcinos y bovinos madurados y fecundados in vitro. Proyecto de investigación:, 2010. SENGER, Phillip L. et al. Pathways to pregnancy and parturition. Current Conceptions, Inc, 2004. SUAREZ, Susan S. The oviductal sperm reservoir in mammals: mechanisms of formation. Biology of Reproduction, v. 58, n. 5, p. 1105-1107, 1998. VALENCIA MÉNDEZ, Javier de J. Fisiología de la reproducción porcina. 1986. -/- FIXAÇÃO DO ASSUNTO -/- 1. Defina e diferencie fertilização e segmentação. -/- 2. Disserte sobre o transporte do ovócito. Por que no istmo o transporte do ovócito se torna lento? -/- 3. Fale sobre a eficiência do transporte do gameta no trato genital da fêmea e sobre a retenção de ovócitos pela égua. -/- 4. Defina as células do cumulus e explique seu papel sobre o ovócito. -/- 5. Quais as estruturas que compõem o ovócito? Qual a função de cada uma? -/- 6. Todos os ovócitos das fêmeas domésticas são iguais? Justifique. -/- 7. Disserte sobre o papel dos hormônios e das secreções sobre o transporte do ovócito no trato genital da fêmea. -/- 8. Disserte sobre o transporte do espermatozoide. Por que há transporte rápido e lento dos espermatozoides? -/- 9. Fale sobre o local de deposição do sêmen nas espécies domésticas e como esse influen-cia na eficiência da reprodução. -/- 10. Por que a vida média do espermatozoide canino é maior que as outras espécies? -/- 11. Quais as mudanças que os espermatozoides precisam sofrer para conseguir êxito na fertilização e por quê? -/- 12. Defina fase de transporte rápido, fase sustentada e hipermotilidade. Qual a importân-cia de cada um? -/- 13. Como ocorre a reação acrossômica? -/- 14. O que é polispermia e como ocorre seu bloqueio? 15. Como ocorre a ativação do ovócito e como se formam os pronúcleos? -/- 16. O que é e qual a importância da singamia? -/- 17. Disserte sobre as divisões de segmentação e qual a importância destas para o êxito da reprodução. -/- 18. Defina e diferencia mórula e blastocisto. -/- 19. Defina e diferencie ginogênese e partenogênese. -/- 20. Qual o papel endócrino e quais hormônios e enzimas atuam sobre o transporte de gametas, sobre a fertilização e sobre a segmentação? (shrink)

In modernity, the distinction between nature and artifice disappears, so that machines made by men become privileged models for the explanation of natural bodies, as can be observed in Bacon, Descartes, Hobbes, among others. This new relationship between nature and artifice is correlated with the mechanization and refutation of finality in nature, insofar as the adoption of mechanics as a model of nature’s explanation is associated to the rejection of the use of final causes in physics and to the conception (...) that bodies are devoid of immanent principles of movement or of any incorporeal principle that predisposes them to a process of change teleologically structured and oriented. Leibniz also conceives nature as artifice and organic bodies as automata, but his conception of natural bodies as artificial machines goes even further, to the point of characterizing the natural beings as those which carry the character of artificial rather than the artificial things themselves. However, unlike Bacon, Descartes, and Hobbes, Leibniz uses the analogy of nature as a machine and deepens it precisely to argue that nature is teleologically structured and that the difference between the machines made by men and the natural (divine) ones lies in the fact that while those have a purely extrinsic finality, these have an immanent finality inscribed in each of their parts to infinity. (shrink)

Recently, there have been calls to develop a more contextual approach to phenomenological psychopathology—an approach that attends to the socio-cultural as well as personal and biographical factors that shape experiences of mental illness. In this Perspective article, we argue that to develop this contextual approach, phenomenological psychopathology should adopt a new paradigm case. For decades, schizophrenia has served as the paradigmatic example of a condition that can be better understood through phenomenological investigation. And recent calls for a contextual approach continue (...) to use schizophrenia as their primary example. We argue, in contrast, that substance misuse provides a better paradigm case around which to develop a contextually sensitive phenomenological psychopathology. After providing a brief vignette and analysis of a case of substance misuse, we explain why this kind of condition requires considerable sensitivity and attention to context, better motivating the incorporation and development of new contextually sensitive approaches. (shrink)

Over the past few decades, Indigenous communities have successfully campaigned for greater inclusion in decision-making processes that directly affect their lands and livelihoods. As a result, two important participatory rights for Indigenous peoples have now been widely recognized: the right to consultation and the right to free, prior and informed consent (FPIC). Although these participatory rights are meant to empower the speech of these communities—to give them a proper say in the decisions that most affect them—we argue that the way (...) these rights have been implemented and interpreted sometimes has the opposite effect, of denying them a say or ‘silencing’ them. In support of this conclusion we draw on feminist speech act theory to identify practices of locutionary, illocutionary, and perlocutionary group silencing that arise in the context of consultation with Indigenous communities. (shrink)

Recent feminist philosophy of language has highlighted the ways that the speech of women can be unjustly impeded, because of the way their gender affects the uptake their speech receives. In this chapter, I explore how similar processes can undermine the speech of a different sort of speaker: Indigenous communities. This involves focusing on Indigeneity rather than gender as the salient social identity, and looking at the ways that group speech, rather than only individual speech, can be unjustly impeded. To (...) do this, I make use of the notion of ‘discursive injustice’ that has been developed by Quill Kukla, and, with reference to three case studies, show how discursive injustice can effectively derail the speech of Indigenous communities. (shrink)

According Philip Pettit, suitably organised groups not only possess ‘minds of their own’ but can also ‘make up their minds’ and 'speak for themselves'--where these two capacities enable them to perform as conversable subjects or 'persons'. In this paper I critically examine Pettit's case for group personhood. My first step is to reconstruct his account, explaining first how he understands the two capacities he considers central to personhood – the capacity to ‘make up one’s mind’, and the capacity to ‘speak (...) for oneself’ – before showing how he thinks these can be manifested in groups. With Pettit’s account duly reconstructed, I then turn to criticism, arguing that Pettit’s construal of making up one’s mind does not do proper justice to our first-personal self-understanding, nor to our characteristic interpersonal forms of engagement. This leads me, finally, to consider an alternative construal of ‘making up one’s mind’ and ‘speaking for oneself’ that is associated with the work of Richard Moran and whichargue, could usefully be exteextended to groups. (shrink)

Analisa a atuação de algumas das principais militantes e organizações que construíram a história do feminismo no Brasil, situando sua atuação no processo de transformação vivido pela sociedade brasileira a partir do final do século XIX.

If emotion is not an arbitrary compilation of fixed types of (descriptive, conceptual, conative, prescriptive) content, nor a state that can be reduced to other types of pre-existing (perceptual, cognitive, behavioral) states, then what sort of thing is it really? Tom Cochrane has proposed that emotions are valent representations of situated concerns. Valent representation is a type of mental content whose function is to detect the presence or absence of certain conditions; what makes that type of content valent is that (...) without needing the mediation of any other state, a response is triggered that is disposed to increase or decrease the presence of the condition represented. I raise doubts about the plausibility of that account in light of recent work in philosophy of biology and philosophy of mind. (shrink)

Empathy is a topic of continuous debate in the nursing literature. Many argue that empathy is indispensable to effective nursing practice. Yet others argue that nurses should rather rely on sympathy, compassion, or consolation. However, a more troubling disagreement underlies these debates: There’s no consensus on how to define empathy. This lack of consensus is the primary obstacle to a constructive debate over the role and import of empathy in nursing practice. The solution to this problem seems obvious: Nurses need (...) to reach a consensus on the meaning and definition of empathy. But this is easier said than done. Concept analyses, for instance, reveal a profound ambiguity and heterogeneity of the concept of empathy across the nursing literature. Since the term “empathy” is used to refer to a range of perceptual, cognitive, emotional, and behavioral phenomena, the presence of a conceptual ambiguity and heterogeneity is hardly surprising. Our proposal is simple. To move forward, we need to return to the basics. We should develop the concept from the ground up. That is, we should begin by identifying and describing the most fundamental form of empathic experience. Once we identify the most fundamental form of empathy, we will be able to distinguish among the more derivative experiences and behaviors that are addressed by the same name and, ideally, determine the place of these phenomena in the field of nursing. The aim of this article is, consequently, to lay the groundwork for a more coherent concept of empathy and thereby for a more fruitful debate over the role of empathy in nursing. In Part 1, we outline the history of the concept of empathy within nursing, explain why nurses are sometimes warry of adapting concepts from other disciplines, and argue that nurses should distinguish between adapting concepts from applied disciplines and from more theoretical disciplines. In Part 2, we show that the distinction between emotional and cognitive empathy—borrowed from theoretical psychology—has been a major factor in nurses’ negative attitudes toward emotional empathy. We argue, however, that both concepts fail to capture the most fundamental form of empathy. In Part 3, we draw on and present some of the seminal studies of empathy that can be found in the work of phenomenological philosophers including Max Scheler, Edmund Husserl, and Edith Stein. In Part 4, we outline how their understanding of empathy may facilitate current debates about empathy’s role in nursing. (shrink)

Resolving to finish reading a novel, staying true to your punk style, or dedicating your life to an artistic project: these are examples of aesthetic commitments. I develop an account of the nature of such commitments, and I argue that they are significant insofar as they help us manage the temporally extended nature of our aesthetic agency and our relationships with aesthetic objects. At the same time, focusing on aesthetic commitments can give us a better grasp on the nature of (...) aesthetic normativity; this is because, in making aesthetic commitments, we are capable of giving aesthetic concerns the weight of obligation. I argue that appealing to aesthetic commitments allows us to account for the existence of aesthetic obligations as well as their grounding. I conclude by arguing that, although the aesthetic domain is a domain of play and freedom of choice, there is nevertheless an important place in it for both aesthetic commitments and the aesthetic obligations they generate. (shrink)

Jack Spencer has recently argued for the striking thesis that, possibly, an agent is able to do the impossible—that is, perform an action that is metaphysically impossible for that person to perform. Spencer bases his argument on (Simple G), a case in which it is impossible for an agent G to perform some action but, according to Spencer, G is still intuitively able to perform that action. I reply that we would have to give up at least four action-theoretical principles (...) if we accept that G is able to do the impossible. We may be best off retaining the principles and thus rejecting Spencer's intuition that G is able to do the impossible. I then consider an argument for the claim that G is able to do the impossible that goes through the Snapshot Principle. I, however, deny that any true variant of the Snapshot Principle shows that G is able to do the impossible. Moreover, the counterexample to the Snapshot Principle that I develop also suggests that G is unable to do the impossible in (Simple G). The most natural explanation for why an agent is unable to perform some action in this counterexample extends to (Simple G). Next, I develop three error theories for why we might initially share Spencer's intuition that G is able to do the impossible in (Simple G). Finally, I consider a couple other "G-cases" of Spencer's and find them all wanting. Perhaps we are unable to do the impossible. (shrink)

Is it possible to donate unpaired vital organs, foreseeing but not intending one's own death? We argue that this is indeed psychologically possible, and thus far agree with Charles Camosy and Joseph Vukov in their recent paper on 'double effect donation.' Where we disagree with these authors is that we see double effect donation not as a morally praiseworthy act akin to martyrdom but as a morally impermissible act that necessarily disrespects human bodily integrity. Respect for bodily integrity goes beyond (...) avoiding the aim to kill: not all side effects of deliberate bodily interventions can be outweighed by intended benefits for another even if the subject fully consents. It is not any necessary intention to kill or harm another or oneself that makes lethal donation/harvesting illicit but the more immediate intention to accept or perform surgery on an (innocent) person combined with the foresight of lethal harm and no health-related good for him or her. Double effect donation falls foul of the first condition of double effect reasoning in that the immediate act is wrong in itself. We argue further that the wider effects of such donation would be socially disastrous and corrupting of the medical profession: doctors should retain a sense of nonnegotiable respect for bodily integrity even when they intervene on willing subjects for the benefit of others. (shrink)

Politics, Philosophy & Economics, Volume 21, Issue 4, Page 347-371, November 2022. We sometimes have to choose between options that are seemingly incomparable insofar as they seem to be neither better than, worse than, nor equal to each other. This often happens when the available options are quite different from one another. For instance, consider a choice between prioritizing either criminal justice reform or healthcare reform as a public policy goal. Even after the relevant details of the goals and possible (...) reforms are filled in, it is plausible that neither goal is better than, worse than, nor equal to the other. Such seemingly incomparable options present a problem for rational choice since it is unclear how an agent might rationally choose between them. What we need are some principles to help govern rational choice when faced with seemingly incomparable options. I here present three such principles. While each principle is individually compelling, I show that they are jointly incompatible. I then argue that the correct response to this inconsistent triad is to reject the principle that rationally censures performing a sequence of choices one knows will result in a suboptimal outcome. The upshot is that when seeming incomparability is involved, an agent can money pump themselves without being less rational for it. (shrink)

An attractive form of social stability is realized when the members of a well-ordered society give that society’s organizing principles their free and reflective endorsement. However, many political philosophers are skeptical that there is any requirement to show that their principles would engender this kind of stability. This skepticism is at the root of a number of objections to political liberalism, since arguments for political liberalism often appeal to its ability to be stable in this way. The aim of this (...) paper is to address skepticism about the stability condition by putting forward a novel defense of it. My defense builds on the claim that stable principles are necessary to secure the full autonomy of those who live under them. (shrink)

In both The Right and the Good and The Foundations of Ethics, W. D. Ross maintains that any amount of the non-instrumental value of virtue outweighs any amount of the non-instrumental value of pleasure or avoidance of pain. The chapter raises two challenges to the status that Ross accords the value of virtue relative to the value of pleasure (pain). First, it argues that Ross fails to provide a good argument for thinking that virtue is always better than pleasure and (...) that it is in any case implausible to think that any amount of virtue (or avoidance of vice) is better than the avoidance of any amount of pain or suffering. Second, it argues that the inflexibility of Ross’s value theory exhibited in his claim about the relative value of virtue produces tension with and mars the attractive heterarchical structure of his theory of rightness or prima facie duties. (shrink)

Bare plural generic sentences pervade ordinary talk. And yet it is extremely controversial what semantics to assign to such sentences. In this paper, I achieve two tasks. First, I develop a novel classification of the various standard uses to which bare plurals may be put. This “variety data” is important—it gives rise to much of the difficulty in systematically theorizing about bare plurals. Second, I develop a novel account of bare plurals, the radical account. On this account, all bare plurals (...) fail to express propositions. The content of a bare plural has to be pragmatically “completed” by a speaker in order for her to make an assertion. At least the content of a quantifier expression has to be supplied. But sometimes, the content of a sentential operator or modal verb is also supplied. The radical account straightforwardly explains the variety data: Speakers’ communicative intentions vary wildly across different contexts. (shrink)

In this essay I defend the view that Henry Sidgwick’s moral epistemology is a form of intuitionist foundationalism that grants common-sense morality no evidentiary role. In §1, I outline both the problematic of The Methods of Ethics and the main elements of its argument for utilitarianism. In §§2-4 I provide my interpretation of Sidgwick’s moral epistemology. In §§ 5-8 I refute rival interpretations, including the Rawlsian view that Sidgwick endorses some version of reflective equilibrium and the view that he is (...) committed to some kind of pluralistic epistemology. In§ 9 I contend with some remaining objections to my view. (shrink)

Several philosophers have suggested that certain aspects of people’s experience of agency partly explains why people tend to report that it seems to them, in perceptual experience, as though time robustly passes. In turn, it has been suggested that people come to believe that time robustly passes on the basis of its seeming to them in experience that it does. We argue that what require explaining is not just that people report that it seems to them as though time robustly (...) passes, and that they believe that it does, but rather, the substantial variation (a) in people’s reports regarding whether it seems as though time robustly passes, and (b) their beliefs about whether time robustly passes. We empirically investigate the agentive explanation of (a), according to which variation in people’s agentive experiences explains variation in people’s reports regarding whether it seems to them as though time robustly passes. We also empirically investigate the experiential seeming explanation of belief, according to which variation in people’s beliefs about whether time robustly passes is explained by variation in their reports regarding whether it seems in experience as though time robustly passes. We found empirical support for the agentive explanation, but not for the experiential seeming explanation of passage beliefs. We consider the implications of our results for three views about temporal experience and temporal beliefs: dynamism, passage illusionism and deflationism. (shrink)

A review of Anthony Appiah's Experiments in Ethics.

In “The Open Future” (2021) Patrick Todd argues that the future is open, and that as a consequence all future contingents are false (as opposed to the more common view that they are neither true nor false). Very roughly, this latter claim is motivated by the idea that (a) presentism is true, and so future (and indeed past) things do not exist and (b) if future things do not exist, then the only thing that could ground there being future tensed (...) facts, and hence make those future tensed claims true, is the present and the laws of nature. But (c) the present and the laws of nature cannot ground there being future tensed facts because they do not necessitate there being any such fact. Hence future tensed claims are all false. Todd then goes on to present a semantics for his version of the open future on which all future contingents are false. In what follows we take up two strands of Todd’s view. First, we begin, in Section 2, by outlining Todd’s argument that future contingents are all false. We suggest that the considerations that Todd adduces for this conclusion do not support this being so. Then in Section 3 we consider the semantics that Todd offers, and argue that it yields implausible consequences. (shrink)

For much of the first fifty years of its existence, analytic philosophy shunned discussions of normativity and ethics. Ethical statements were considered as pseudo-propositions, or as expressions of pro- or con-attitudes of minor theoretical significance. Nowadays, in contrast, prominent analytic philosophers pay close attention to normative problems. Here we focus our attention on the work of Searle, at the same time drawing out an important connection between Searle’s work and that of two other seminal figures in this development: H.L.A. Hart (...) and John Rawls. We show that all three thinkers tend to assume that there is but one type of normativity within the realm of social institutions – roughly, the sort of normativity that is involved in following the results of chess – and that they thereby neglect features that are of crucial significance for an adequate understanding of social reality. (shrink)

In this chapter, I introduce phenomenology and phenomenological psychopathology by clarifying the kind of implicit experiences that phenomenologists are concerned with. In section one, I introduce the phenomenological concept of pre-reflective experience, focusing especially on its relation to the concept of implicit experience. In section two, I introduce the structure of pre-reflective self-consciousness, which has been studied extensively by both classical phenomenologists and contemporary phenomenological psychopathologists. In section three, I show how phenomenological psychopathologists rely on an account of pre-reflective self-consciousness (...) to better understand the experience of schizophrenia and I outline some of the methodological challenges that arise in this field of research. This introduction should facilitate critical engagement and collaboration between phenomenologists and researchers working across a variety of disciplines, including psychology, psychiatry, the cognitive sciences, and analytic philosophy of mind. (shrink)

We explore the role of episodic imagining in explaining why people both differentially report that it seems to them in experience as though time robustly passes, and why they differentially report that they believe that time does in fact robustly pass. We empirically investigate two hypotheses, the differential vividness hypothesis, and the mental time travel hypothesis. According to each of these, the degree to which people vividly episodically imagine past/future states of affairs influences their tendency to report that it seems (...) to them as though time robustly passes and to judge that time does robustly pass. According to the former, a greater degree of vividness will tend to increase the extent to which people make such reports, while according to the latter, it will tend to decrease the extent to which people make such reports. We found weak evidence in favour of the former hypothesis. We reflect on the implications of this finding for theorising about such reports. (shrink)

Digital technology has prompted philosophers to rethink some of the fundamental categories we use to make sense of the world and ourselves. Particularly, the concept of ‘identity’ and its reconfiguration in the digital age has sparked much debate in this regard. While many studies have addressed the impact of the digital on personal and social identities, the concept of ‘collective identity’ has been remarkably absent in such inquiries. In this article, I take the context of social movements as an entry (...) point to discuss the reconfiguration of collective identity in social media environments. I do so by introducing a narrative approach to collective identity. I argue that Twitter’s affordances invite new ways of constructing collective identities and imply a shifting relationship between the individual and the collective. (shrink)

Two lines of evidence indicate that there exists a reciprocal inhibitory relationship between opposed brain networks. First, most attention-demanding cognitive tasks activate a stereotypical set of brain areas, known as the task-positive network and simultaneously deactivate a different set of brain regions, commonly referred to as the task negative or defaultmode network. Second, functional connectivity analyses show that these same opposed networks are anti-correlated in the resting state. Wehypothesize that these reciprocally inhibitory effects reflect two incompatible cognitive modes, each of (...) which may be directed towards understanding the external world. Thus, engaging onemode activates one set of regions and suppresses activity in the other.Wetest this hypothesis by identifying two types of problem-solving task which, on the basis of prior work, have been consistently associated with the task positive and task negative regions: tasks requiring social cognition, i.e., reasoning about the mental states of other persons, and tasks requiring physical cognition, i.e., reasoning about the causal/mechanical properties of inanimate objects. Social and mechanical reasoning tasks were presented to neurologically normal participants during fMRI. Each task type was presented using both text and video clips. Regardless of presentation modality, we observed clear evidence of reciprocal suppression: social tasks deactivated regions associated with mechanical reasoning and mechanical tasks deactivated regions associated with social reasoning. These findings are not explained by self-referential processes, task engagement, mental simulation,mental time travel or external vs. internal attention, all factors previously hypothesized to explain default mode network activity. Analyses of resting state data revealed a close match between the regions our tasks identified as reciprocally inhibitory and regions of maximal anti-correlation in the resting state. These results indicate the reciprocal inhibition is not attributable to constraints inherent in the tasks, but is neural in origin. Hence, there is a physiological constraint on our ability to simultaneously engage two distinct cognitive modes. Furtherwork is needed tomore precisely characterize these opposing cognitive domains. (shrink)

Musing for Puncta special issue "Critically Sick: New Phenomenologies Of Illness, Madness, And Disability.".

This chapter provides an overview of how existential phenomenology has influenced qualitative research methods across a range of disciplines across the social, health, educational, and psychological sciences. It focuses specifically on how the concepts of “existential structures,” or “existentials”—such as selfhood, temporality, spatiality, affectivity, and embodiment—have been used in qualitative research. After providing a brief introduction to what qualitative research is and why philosophers should be interested in it, the chapter provides clear, straightforward examples of how qualitative researchers have used (...) existentials to analyze qualitative data and design qualitative studies. The chapter is intended to introduce philosophers to existential approaches to phenomenological qualitative research, with the aim of facilitating interdisciplinary dialogue and collaboration. (shrink)

Each annual Ontology Summit initiative makes a statement appropriate to each Summit’s theme as part of our general advocacy designed to bring ontology science and engineering into the mainstream. The theme this year is "Towards an Open Ontology Repository". This communiqué represents the joint position of those who were engaged in the year's summit discourse on an Open Ontology Repository (OOR) and of those who endorse below. In this discussion, we have agreed that an "ontology repository is a facility where (...) ontologies and related information artifacts can be stored, retrieved and managed." -/- We believe in the promise of semantic technologies based on logic, databases and the Semantic Web, a Web of exposed data and of interpretations of that data (i.e., of semantics), using common standards. Such technologies enable distinguishable, computable, reusable, and sharable meaning of Web and other artifacts, including data, documents, and services. We also believe that making that vision a reality requires additional supporting resources and these resources should be open, extensible, and provide common services over the ontologies. (shrink)

Aims and Objectives. This article uses the concept of embodiment to demonstrate a conceptual approach to applied phenomenology. -/- Background. Traditionally, qualitative researchers and healthcare professionals have been taught phenomenological methods, such as the epoché, reduction, or bracketing. These methods are typically construed as a way of avoiding biases so that one may attend to the phenomena in an open and unprejudiced way. However, it has also been argued that qualitative researchers and healthcare professionals can benefit from phenomenology’s well-articulated theoretical (...) framework, which consists of core concepts, such as selfhood, empathy, temporality, spatiality, affectivity, and embodiment. -/- Design. This is a discursive article that demonstrates a conceptual approach to applied phenomenology. -/- Method. To outline and explain this approach to applied phenomenology, the Discussion section walks the reader through four stages of phenomenology, which progress incrementally from the most theoretical to the most practical. -/- Discussion. Part one introduces the philosophical concept of embodiment, which can be applied broadly to any human subject. Part two shows how philosophically trained phenomenologists use the concept of embodiment to describe general features of illness and disability. Part three illustrates how the phenomenological concept of embodiment can inform empirical qualitative studies and reflects on the challenges of integrating philosophy and qualitative research. Part four turns to phenomenology’s application in clinical practice and outlines a workshop model that guides clinicians through the process of using phenomenological concepts to better understand patient experience. -/- Conclusion and Relevance to Clinical Practice. A conceptual approach to applied phenomenology provides a valuable alternative to traditional methodological approaches. Phenomenological concepts provide a foundation for better understanding patient experience in both qualitative health research and clinical practice, and therefore provide resources for enhancing patient care. (shrink)

In this chapter, we explain how Karl Jaspers’ concept of empathy can be expanded by drawing upon the tradition of philosophical phenomenology. In the first section, we offer an account of Jaspers' concepts of empathy and incomprehensibility as he develops them in General Psychopathology and “The Phenomenological Approach in Psychopathology.” In the second section, we survey the recent literature on overcoming Jaspers' notion of incomprehensibility and expanding his concept of empathy. In the third section, we outline the levels of investigation (...) at which phenomenological inquiries into psychopathology may proceed. These levels of human existence are, in descending order of depth, (1) phenomenal experiences, (2) interpretive frameworks, (3) modes of existence, and (4) existentials. In the fourth and final section, we argue that to fully empathically comprehend patients with schizophrenia and other mental disorders, the possibility of alterations at all four levels of existence must be acknowledged. (shrink)

According to Margaret Gilbert, two or more people collectively believe that p if and only if they are jointly committed to believe that p as a body. But the way she construes joint commitment in her account – as a commitment of and by the several parties to “doing something as a body” – encourages the thought that the phenomenon accounted for is not that of genuine belief. I explain why this concern arises and explore a different way of construing (...) joint commitment, in order to avoid the concern. This leads me to propose a revised Gilbertian account of collective belief, according to which two or more people collectively believe that p if and only if they are jointly committed to p as true. (shrink)

Contemporary psychiatry finds itself in the midst of a crisis of classification. The developments begun in the 1980s—with the third edition of the Diagnostic and Statistical Manual of Mental Disorders —successfully increased inter-rater reliability. However, these developments have done little to increase the predictive validity of our categories of disorder. A diagnosis based on DSM categories and criteria often fails to accurately anticipate course of illness or treatment response. In addition, there is little evidence that the DSM categories link up (...) with genetic findings, and even less evidence that they... (shrink)

This paper discusses two approaches to climate ethics for practicalreflection and decision-making in concrete local climate changegovernance. After a brief review of the main conceptual frameworksin climate ethics research, we show that none of these leadingapproaches is sufficiently context specific and pluralistic to provideguidance appropriate for concrete local climate governance. Asalternatives, we present principlism as a methodology of midlevelprinciples and environmental pragmatism as an ethicalapproach. We argue that the two methodologies of principlismand pragmatism offer a new pluralistic framework that allows (...) realworldconditions and contexts to be properly integrated into ethicalanalysis and decision-making in climate governance. (shrink)

In this essay I address the question, “What is the subject matter of phenomenological research?” I argue that in spite of the increasing popularity of phenomenology, the answers to this question have been brief and cursory. As a result, contemporary phenomenologists lack a clear framework within which to articulate the aims and results of their research, and cannot easily engage each other in constructive and critical discourse. Examining the literature on phenomenology’s identity, I show how the question of phenomenology’s subject (...) matter has been systematically neglected. It has been overshadowed by an unending concern with phenomenology’s methodological identity. However, an examination of recent contributions to this literature reveals that a concern with articulating phenomenology’s subject matter has gradually increased, although such articulations remain preliminary. In light of this, I delineate, define, and illustrate three layers of phenomenological research, which I term “existentials,” “modes,” and “prejudices.” While the delineation of these layers is drawn primarily from classical phenomenological texts, they are defined and illustrated through the use of more contemporary literature. Following the articulation of this subject matter, I briefly consider some of the debates—both foundational and applied—that can be facilitated by the adoption of this framework. (shrink)

Adolescents are routinely treated differently to adults, even when they possess similar capacities. In this article, we explore the justification for one case of differential treatment of adolescents. We attempt to make philosophical sense of the concurrent consents doctrine in law: adolescents found to have decision-making capacity have the power to consent to—and thereby, all else being equal, permit—their own medical treatment, but they lack the power always to refuse treatment and so render it impermissible. Other parties, that is, individuals (...) who exercise parental responsibility or a court, retain the authority to consent on an adolescent’s behalf. We explore four defences of the doctrine. We reject two attempts to defend the asymmetry in the power to consent to and refuse medical treatment by reference to transitional paternalism. We then consider and reject a stage of life justification. Finally, we articulate a justification based on the distinctiveness of adolescent well-being. (shrink)

Most recent discussions of reasons in art criticism focus on reasons that justify beliefs about the value of artworks. Reviving a long-neglected suggestion from Paul Ziff, I argue that we should focus instead on art-critical reasons that justify actions—namely, particular ways of engaging with artworks. I argue that a focus on practical rather than theoretical reasons yields an understanding of criticism that better fits with our intuitions about the value of reading art criticism, and which makes room for a nuanced (...) distinction between criticism that aims at universality and criticism that is resolutely personal. (shrink)

In this paper, I explore what gives collective testimony its epistemic credentials, through a critical discussion of three competing accounts of the epistemology of collective testimony. According to the first view, collective testimony inherits its epistemic credentials from the beliefs the testimony expresses— where this can be seen either as the beliefs of all or some of the group’s members, or as the beliefs of group itself. The second view denies any necessary connection to belief, claiming instead that the epistemic (...) credentials of collective testimony derive from the reliability or truth-conduciveness of the statement that expresses the testimony. Finally, the third view claims that the epistemic credentials of collective testimony derive from the fact that it involves undertaking a collective commitment to trustworthiness, which makes the group susceptible to rebuke and blame if its testimony is not trustworthy. I argue that this last account holds the most promise for preserving what is distinctive about testimonial knowledge while still underwriting a robust epistemology of collective testimony. (shrink)

This paper has three main goals. First, to motivate a puzzle about how ignorance-expressing terms like maybe and if interact: they iterate, and when they do they exhibit scopelessness. Second, to argue that there is an ambiguity in our theoretical toolbox, and that exposing that opens the door to a solution to the puzzle. And third, to explore the reach of that solution. Along the way, the paper highlights a number of pleasing properties of two elegant semantic theories, explores some (...) meta-theoretic properties of dynamic notions of meaning, dips its toe into some hazardous waters, and offers characterization theorems for the space of meanings an indicative conditional can have. (shrink)

How is the Sartrean conception of phenomena of anguish connected to what we currently refer to as phenomena of anxiety? And what is the exact interrelation between anguish, fear, and anxiety?

In this article, I argue that phenomenological psychopathologists, despite their critical attitude toward mainstream psychiatry, still hold problematic prejudices about the nature of psychiatric conditions as illness or disorder. I suggest that phenomenological psychopathologists turn to resources in the neurodiversity and mad pride movements to critically reflect upon these prejudices and appreciate the methodological problems that they pose.

In this paper I offer an alternative phenomenological account of depression as consisting of a degradation of the degree to which one is situated in and attuned to the world. This account contrasts with recent accounts of depression offered by Matthew Ratcliffe and others. Ratcliffe develops an account in which depression is understood in terms of deep moods, or existential feelings, such as guilt or hopelessness. Such moods are capable of limiting the kinds of significance and meaning that one can (...) come across in the world. I argue that Ratcliffe’s account is unnecessarily constrained, making sense of the experience of depression by appealing only to changes in the mode of human existence. Drawing on Merleau-Ponty’s critique of traditional transcendental phenomenology, I show that many cases of severe psychiatric disorders are best understood as changes in the very structure of human existence, rather than changes in the mode of human existence. Working in this vein, I argue that we can make better sense of many first-person reports of the experience of depression by appealing to a loss or degradation of the degree to which one is situated in and attuned to the world, rather than attempting to make sense of depression as a particular mode of being situated and attuned. Finally, I argue that drawing distinctions between disorders of structure and mode will allow us to improve upon the currently heterogeneous categories of disorder offered in the DSM-5. (shrink)

The aesthetic domain is a social one. We coordinate our individual acts of creation, appreciation, and performance with those of others in the context of social aesthetic practices. More strongly, many of the richest goods of our aesthetic lives are constitutively social; their value lies in the fact that individuals are engaged in joint aesthetic agency, participating in cooperative and collaborative project that outstrips what can be realized alone. I provide an account of nature and value of two such social (...) aesthetic goods—aesthetic communities and aesthetic traditions—and further argue that such goods are a core constituent of an aesthetically good life. At the same time, I argue that the ideals of the dominant theory of aesthetic value, aesthetic value hedonism, are incompatible with a full commitment to these social aesthetic goods; the hedonist is thereby alienated from the other participants within aesthetic communities and traditions. This sets up a dilemma for the hedonist: either the hedonist must bite the bullet, accepting that the theory leads to a problematic form of aesthetic alienation; or, we must reject aesthetic value hedonism and adopt a different theory of aesthetic value which accommodates the value of social aesthetic goods. I argue that we should take the second horn of the dilemma. (shrink)

Jennifer Lackey (2018) has developed an account of the primary form of group assertion, according to which groups assert when a suitably authorized spokesperson speaks for the group. In this paper I pose a challenge for Lackey's account, arguing that her account obscures the phenomenon of group silencing. This is because, in contrast to alternative approaches that view assertions (and speech acts generally) as social acts, Lackey's account implies that speakers can successfully assert regardless of how their utterances are taken (...) up by their audiences. What reflection on group silencing shows us, I argue, is that an adequate account of group assertion needs to find a place for audience uptake. (shrink)

“On the Subject Matter of Phenomenological Psychopathology” provides a framework for the phenomenological study of mental disorders. The framework relies on a distinction between (ontological) existentials and (ontic) modes. Existentials are the categorial structures of human existence, such as intentionality, temporality, selfhood, and affective situatedness. Modes are the particular, concrete phenomena that belong to these categorial structures, with each existential having its own set of modes. In the first section, we articulate this distinction by drawing primarily on the work of (...) Martin Heidegger—especially his study of the ontological structure of affective situatedness (Befindlichkeit) and its particular, ontic modes, which he calls moods (Stimmungen). In the second section, we draw on a study of grief to demonstrate how this framework can be used when conducting phenomenological interviews and analyses. In the concluding section, we explain how this framework can be guide phenomenological studies across a broad range of existential structures. (shrink)

Both proponents and critics of the desire theory of welfare have narrowly focused on the positive side of the theory while virtually ignoring its negative side. On the positive side, the desire theorist says that getting what you want is good for you. But what should the desire theorist say is bad for you? A common and plausible-sounding answer is that if getting what you want is good for you, then surely not getting what you want is bad for you. (...) I argue that this answer is a mistake that would commit desire theorists to a claim that is implausible by their own lights, namely that a state of affairs could be bad for you even if you were not at all bothered by it. The desire theorist should instead say that getting what you are averse to is bad for you. If desire satisfaction is good for you, then aversion satisfaction, not desire frustration, is bad for you. (shrink)

Human beings are by nature enshrined in an inescapable world - hood web called language. As a symbolic construction and human agenda setting in semantic space, language ensures the application of social meaning, control, culture and social knowledge. As a re sult of the place that language occupies in the integration, interpretation and internalization of convention for the state of affairs of sociality, it is not surprising that it has always been an attractive area and a fascinating topic for philosophers. (...) T he history of philosophical thinking about language is almost impossible to separate from the history of logic and indeed the entire history of philosophy. This piece argued that human beings do not live in the world without the agency of language which be comes the medium of expression within particular societies. It is based on this understanding (that the real world of a people is based on their language habits) that this paper employed Igwebuike as an ontological toolbox that forms the trajectory system of the Igbo - African world. Within the context of Igbo - African philosophy of language, this piece argued for the necessity of the use of the word “Igwebuike” as it captures and communicates the Igbo - African world. Igwebuike is the form (and symbolic) of the Igbo - African mental being, and thus, the gateway to Igbo - African philosophy. Beyond the literal understanding of Igwebuike (Igwe - number; bu - is; ike - strength) as ‘there is strength in number’, it captures the Igbo philosophy of relationality, complementar ity and interconnectedness of reality. The objective of this work is to discover the centrality of language within philosophy and thus give correct bearing to philosophy. For the purpose of this piece, the Igwebuike holistic approach will be employed. (shrink)