In contrast to the successful previous year, 2020 turned out to be difficult, not only for the earth’s population due to COVID-19 but also for JDDM with an unusually small sixth volume. Looking back at these two very different years back-to-back led us to some reflection: As the COVID-19 pandemic forcefully illustrates, dynamic decision-making with all its complications and uncertainty is a topic of high relevance for modern societies.

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)

İslam dininin kutsal kitabı olan Kur’an-ı Kerim’in Orta Çağ Hristiyan Batı dünyasında yüzyıllar boyu ön kabullerle incelendiği ve uzun polemiklere konu edildiği bilinmektedir. Kur’an’ın farklı ve nispeten daha objektif okumaları ancak Aydınlanma dönemi sürecin-de kilisenin hegemonyasının kırılması sonrasında mümkün olabilmiştir. Alman şair Jo-hann Wolfgang von Goethe (1749-1832) bu yeni perspektifin en önemli temsilcilerinden biridir. Gençlik yıllarından itibaren Kur’an ile meşgul olan Goethe, farklı meallere ve kaynaklara da müracaat ederek Kur’an hakkında zengin bir bilgi birikimine sahip olmuş-tur. Yapılacak yüzeysel bir (...) inceleme, onun Kur’an ve İslam dünyasından aldığı ilhamları meşhur Doğu-Batı Divanı’nda şiirlerine yansıttığını göstermeye yetecektir. Elinizdeki bu makalede kısaca Kur’anʼın Hristiyan Batı dünyasındaki algısı anlatılacak, ardından Goet-he’nin Kur’an ile olan meşguliyeti ortaya konulacaktır. Son bölümdeyse, Kur’an’ın Doğu-Batı Divanı’ndaki yansımalarının izi sürülecektir. (shrink)

Our senses provide us with information about the world, but what exactly do they tell us? I argue that in order to optimally respond to sensory stimulations, an agent’s doxastic space may have an extra, “imaginary” dimension of possibility; perceptual experiences confer certainty on propositions in this dimension. To some extent, the resulting picture vindicates the old-fashioned empiricist idea that all empirical knowledge is based on a solid foundation of sense-datum propositions, but it avoids most of the problems traditionally associated (...) with that idea. The proposal might also explain why experiences appear to have a non-physical phenomenal character, even if the world is entirely physical. (shrink)

The central idea of this essay is that philosophical thinking revolves around aporetic clusters, i.e., sets of individually plausible, but collectively inconsistent propositions. The task of philosophy is to dissolve such clusters, either by showing that the propositions in question, contrary to first impression, are compatible with each other, or by showing that it is permissible to abandon at least one of the propositions involved. This view of philosophical problems not only provides a very good description of well-understood philosophizing, but (...) is also better suited than others to explain some seemingly strange characteristics of philosophy, most notably its armchair character, the large variety of incommensurable doctrines by which it is characterized, and its concern with its own history. (shrink)

According to the transparency approach, achievement of self-knowledge is a two-stage process: first, the subject arrives at the judgment ‘p’; second, the subject proceeds to the judgment ‘I believe that p.’ The puzzle of transparency is to understand why the transition from the first to the second judgment is rationally permissible. After revisiting the debate between Byrne and Boyle on this matter, I present a novel solution according to which the transition is rationally permissible in virtue of a justifying argument (...) that begins from a premise referring to the mental utterance that is emitted in the course of judging ‘p.’. (shrink)

The creation of new institutions and the initiation of new forms of behaviour cannot be explained only on the basis of constitutive rules – they also require a broader commitment of individuals who participate in social practices and, thus, to become members of a community. In this paper, I argue that the received conception of constitutive rules shows a problematic intellectualistic bias that becomes particularly manifest in three assumptions: (i) constitutive rules have a logical form, (ii) constitutive rules have no (...) normative force, and (iii) rules are essentially tied to a sanctioning authority. I discuss these three claims in light of real-life examples. The goal of this discussion is to show that the normative force of constitutive rules is based on the shared commitment of participants who engage in the relevant practices. The inner cohesion and the persistence in time of these practices is possible only because participants continuously calibrate their own forms of behaviour to that of the other members of the community, which underscores the social dimension of constitution. (shrink)

Kendall Walton’s account of make-believe takes the social dimension of imagination into account. In this paper I aim to extend this suggestion and argue that works of fiction allow for encounters with concrete (yet fictitious) persons with a distinct point of view and a discernible perspective. These encounters allow us to contrast the perspective(s) that emerge from the work with one’s own. I will then discuss two moments of the social dimension: imagining fictional scenarios is a social practice, a game (...) we play together and in which we encounter others. Both of these moments shed light on the central role of fiction for the social community in which it is embedded and show how engaging with works of fiction can contribute to the inner cohesion and to the persistence of the group. (shrink)

The ontology of marketing, particularly the question of what products and brands are, is still largely unexplored. The ontological status of brands hinges on their relationship with products. Idealists about brands see perceptual or cognitive acts of consumers grouped under the heading ‘brand awareness’ or ‘brand image’ as constitutive for the existence of brands so that, in their view, tools of the marketing mix can influence relevant mental dispositions and attitudes. Brand realists, on the other hand, reject the view of (...) brands as mere marks or names and interpret them as emergent products with properties that afford branding in the sense of Gibson’s ecological psychology. Brand strength is a function of the degree to which brands occupy defensible niches in product space. Branding as a process involves changing external or internal boundaries of products. Several arguments are proposed in favor of brand realism. The fragments of an ontology of marketing are developed in a broadly Aristotelian framework. Brand realism has significant implications for a new understanding of issues ranging from the effects of advertising to financial brand valuation, the nature of trademarks, and marketing strategy in general. It permits one to treat brand equity as a real phenomenon not dependent on associations, attitudinal states such as brand loyalty, or spurious constructs such as brand character or personality. (shrink)

Many philosophical theories of self-knowledge can be understood as attempts to explain why self-ascriptions enjoy a certain kind of authority that other-ascriptions lack (the Authority Thesis). The aim of this paper is not to expand the stock of existing explanations but to ask whether the Authority Thesis can be adequately specified. To this end, I identify three requirements that must be met by any satisfactory specification. I conclude that the search for an adequate specification of the Authority Thesis leads to (...) a dilemma: it either yields an interpretation under which the thesis is philosophically interesting but false, or it produces an interpretation under which the thesis is actually true but of minor philosophical interest. (shrink)

Evolutionary theory usually neglects two variables: the changes induced in the environment by the evolving organism, and individual uniqueness in sexually reproducing species. In order to fuel its maintenance and reproduction, an organism must average a positive net energy balance vis-a-v}s its environment. It achieves this via aptations, which consist of information (i.e., the internalization of all that is predictable about the environment, including the machinery to take advantage of this information) and stored energy (to operate the machinery, including a (...) safety margin to deal with events that are unpredictable in principle). Taking advantage of a prediction, however, interferes with what has been predicted; each adaptation by the organism therefore changes its environmental target. Today's organism is adapted to yesterday's environment, and today's predator inherits yesterday's prey image. This paper attempts to show that, over evolutionary time, the persistence of this asymmetric, time-lagged relationship is owed increasingly to genetically unique individuals. Individual uniqueness as resulting from sexual reproduction is janusfaced. It endows an evolving population with both a forward-looking (promethean) and backward-looking (protean) feature. A population made up of genetically unique individuals is promethean (creative) in its ability to exploit non-homogeneous resources and respond serendipitously to environmental change via new genotypes; it is protean (elusive) in presenting a pursuer (predator or parasite) with a scattered target. Furthermore, because of the asymmetry between the winnowing of the target gene pool by the pursuer, and the genetic fixation in the pursuer of an outdated target image, the target keeps evolving away from the pursuer at a speed and in a direction that are a function of the pursuer's success. This mechanism ensures an evolutionary time lag be102 W. Sterrer tween pursuer and target, which explains escalation, the stability of asymmetric coevolutionary systems such as the life/dinner principle, and the pervasiveness of the Red Queen effect. Individuality thus both promotes and retards the speed of evolution. Having probably originated simultaneously with predation, sex-generated individuality is a self-accelerating evolutionary process that may account for much of today's organismic and environmental complexity. (shrink)

The contemporary debate in the philosophy of literature is strongly shaped by the anticognitivist challenge, according to which works of literary fiction (that contain propositions that are neither literally true nor affirmed by the author) cannot impart (relevant) knowledge to the readers or enrich their worldly understanding. Anti-cognitivists appreciate works of literary fiction for their aesthetic values and so risk to reduce them to mere ornaments that are entertaining, but eventually useless. Many philosophers have reacted to this challenge by pointing (...) at ways in which works of literary fiction can be informative even though they lack worldly reference: it has been argued, for example, that works of fictions are thought experiments; that they add not to our theoretical knowledge, but to our know-how or to our phenomenal knowledge; or that that they help readers to understand the perspectives of others. A stubborn defense of literary cognitivism, however, risks to collapse into an instrumental understanding of literature. In my paper I suggest that both sides in the debate focus too narrowly on semantic features of the works in question that is tied to what I will call the “referential picture” of language. A shift perspective is needed: for one, we ought to fully appreciate that the term “literature” does not refer to a homogeneous phenomenon, but rather to a very heterogeneous and multifarious set of works that are read by many different readers for many different reasons in many different ways. Second, we need to understand that these works have in common much more than the semantic peculiarity of lacking worldly reference: they are a unique means of communication between authors and readers – and in particular the role of the latter is often neglected in contemporary debate. These two points should help us to get a more comprehensive understanding of the practice of literature and the vast range of values we can find works of literary fiction – and the interplay between them. (shrink)

The present essay seeks, by way of the Austrian example, to make a contribution to what might be called the philosophy of the supranational state. More specifically, we shall attempt to use certain ideas on the philosophy of Gestalten as a basis for understanding some aspects of that political and cultural phenomenon which was variously called the Austrian Empire, the Habsburg Empire, the Danube Monarchy or Kakanien.

This paper aims to support my (2018) skeptical position on the possibility of a correct and philosophically significant specification of first-person authority. For this purpose, I critically examine the proposals presented by Doyle (2021) and Winokur (2022) in response to my position and argue that while these proposals contain some ingenious ideas, they ultimately fall short of providing correct and philosophically significant specifications. Ultimately, the search for an adequate specification of first-person authority remains unresolved.

Narrativity is basically linked to the dynamics of the events and actions which are told and it depends on the pragmatic context, mainly on the narrator and his audience, i.e. on the discursive setting. These dynamics ask for an adequate theoretical frame, e.g. in the format of dynamical system theory or vector analysis. Furthermore, narrativity can be manifested in different modalities. We shall present some specimens of analysis in the linguistic modality (spontaneous oral tales, folktales), in the visual modality (painting (...) by Leonardo da Vinci, action movie in the series of Bond films), and in the musical modality (Blues music). The static analyses in the tradition of structuralism are replaced by morphodynamic schemes, by gesture and glance vectors, paths of pursuit and scenarios of conflict in action movies and eventually by harmonic sequences in the Blues. In this dynamic perspective, the notion of narrativity gains a different profile and it is freed from the preference for linguistic or logical categories. (shrink)

We argue that Wittgenstein’s philosophical perspective on Gödel’s most famous theorem is even more radical than has commonly been assumed. Wittgenstein shows in detail that there is no way that the Gödelian construct of a string of signs could be assigned a useful function within (ordinary) mathematics. — The focus is on Appendix III to Part I of Remarks on the Foundations of Mathematics. The present reading highlights the exceptional importance of this particular set of remarks and, more specifically, emphasises (...) its refined composition and rigorous internal structure. (shrink)

Abstract: Brentano’s conception of scientific philosophy had a strong influence on his students and on the intellectual atmosphere of Vienna in the late nineteenth century. The aim of this article is to expose Brentano’s conception and to contrast his views with that of two traditions he is said to have considerably influenced: phenomenology and analytic philosophy. I will shed light on the question of how and to what extent Brentano’s conception of philosophy as a rigorous science has had an impact (...) on these two traditions. The discussion will show that both took their liberties in the interpretation of the thesis, a move that allowed them to liberate themselves from Brentano’s inheritance and to fully develop their own philosophical positions. (shrink)

Brentano’s position in the history of philosophy is often illustrated by the long list of important philosophers who have studied with him. Yet, the relations between Brentano and his students were not always without friction. In the present article I argue that Brentano’s students were most attracted by his conception of a scientific philosophy, which promised to leave the received tradition (German Idealism) behind and to mark the beginning of a new period in the history of philosophy – a project (...) they were happy to be part of. Brentano’s work remained in an important sense fragmentary, however, and could, thus, not provide the inner unity that would have been essential for forming a compact school or a unified philosophical movement. (shrink)

The aim of this paper is to take a fresh look at a discussion about the distinct existences argument that took place between David Armstrong and Frank Jackson more than fifty years ago. I will try to show that Armstrong’s argument can be successfully defended against Jackson’s objections (albeit at the price of certain concessions concerning Armstrong’s view on the meaning of psychological terms as well as his conception of universals). Focusing on two counterexamples that Jackson put forward against Hume’s (...) principle (which is central to Armstrong’s argument), I will argue that they are either compatible with Hume’s principle, or imply a false claim. I will also look at several other considerations that go against Hume’s principle, such as, for example, Kripke’s origin essentialism and counterexamples from aposteriori necessity. (shrink)

Since their formulation by Keith DeRose (1992), the so-called bank cases have played a major role in the discussion about whether knowledge depends on practical factors. According to the proponents of pragmatic encroachment, the proper conclusion to be drawn from the bank cases and similar examples is that knowledge of a proposition _p_ does not supervene on one’s evidence for or against _p_. In my view, this conclusion is ill-founded. The reason is that the bank cases and similar examples suffer (...) from an ambiguity concerning the known proposition — an ambiguity that has so far been overlooked. When this ambiguity is made explicit, it becomes clear that the conclusion does not follow. (shrink)

In a series of recent contributions it has been argued that Franz Brentano’s philosophical position constituted a unified system; Uriah Kriegel has called Brentano's philosophy as “the last grand system of Western philosophy”. The goal of the present paper is to scrutinise this claim and shed light on Brentano's methodological approach and his style of reasoning. I pay particular attention to two aspects: Brentano’s view that philosophy should be done in a rigorous, scientific manner and the fragmentary character of Brentano’s (...) work. I argue that both aspects stand in contrast to the very idea of system-philosophy: the maxim that philosophy should adopt the method of the natural sciences was intended by Brentano as a way of distancing himself from system-philosophy; while the fragmentary character of Brentano’s work does not fulfill the aspiration of system-philosophy to provide an answer to everything. Yet, the incompleteness of his work is not an arbitrary or contingent aspect; it is rather a necessary side-effect of his methodological views. (shrink)

A brief introductory note to the special issue of the Journal of Philosophy on "Parts and Wholes", setting the background for the seven papers included in the rest of the issue (by K. Fine, H. Hudson, M. Johnston, K. Koslicki, C. Normore, P. M. Simons, and P. van Inwagen).

Deleuze’ün Spinozacı yaşam tahayyülünde ‘ne yapmalıyız?’ sorusuna normatif, ahlaki ya da siyasi bir yanıt bulamıyoruz ama varoluşu düşünmenin içkin bir olanağını keşfediyoruz. Düşünmeye 'dışarıdan' yani dünyadan başlamak insani (kurgusal) bir dünyaya değil, içinde yaşadığımız gerçek dünyaya inanmak demektir. İçkinliğin politik anlamı düşünceyi dünyaya getirmektir.

This article aims to show that Williamson's anti-luminosity argument does not succeed if we presuppose a constitutive connection between the phenomenal and the doxastic. In contrast to other luminists, however, my strategy is not to critically focus on the refined safety condition in terms of degrees of confidence that anti-luminists typically use in this context. Instead, I will argue that, given a certain conception of what Chalmers calls ‘direct phenomenal concepts,’ luminosity is guaranteed even if the refined safety condition in (...) terms of degrees of confidence is taken for granted. (shrink)

(For the English version, see below) Dieser Band schließt an die "Prozessontologie" von Wolfgang Sohst an. In vorliegenden Buch entwickelt er den Begriff der Emergenz auf der Grundlage einer Schichtenontologie. Kern dieser Theorie ist der Nachweis, dass die Struktur alles Gegebenen (also nicht nur des physischen Universums, sondern auch der irdischen Biosphäre und der aus ihr hervorgegangenen psychischen, sozialen und abstrakten Existenzformen) offen ist; es gibt keine absolute Entwicklungsgrenze der Weltstruktur. Alles Gegebene ist allerdings in Schichten gegliedert, beginnend mit (...) den protophysikalischen Weltzuständen über die quantenmechanische, die makrophysikalische und biologische Ebene bis hin zu den sozialen Strukturen menschlicher Wirklichkeit und den noch über sie hinausgehenden abstrakten Strukturen der reinen Symbolsysteme. -/- Der Begriff der Emergenz spielt hierin eine wichtige Rolle. Seine ideengeschichtliche Entwicklung seit den 1920er Jahren verlief allerdings unglücklich, weil von vornherein auf neue Einzelgegenstände und ihre Eigenschaften fixiert. Dabei ging sowohl die Prozesshaftigkeit der Welt verloren als auch die Einsicht, dass neue Strukturschichten der Welt nicht durch einzelne Gegenstände oder ihre Eigenschaften repräsentiert werden, sondern durch neue Gegenstands-, Zustands- und Prozesstypen. Dieser zunächst unauffällig erscheinende Unterschied zur traditionellen Emergenztheorie eröffnet vollkommen neue Zugänge und Verständnismöglichkeiten zur strukturellen Entwicklung des Weltganzen. (560 Seiten, Hardcover) -/- English version: This volume follows on from Wolfgang Sohst's "Process Ontology". In this book, he develops the concept of emergence on the basis of a layered ontology. The core of this theory is the proof that the structure of everything given (i.e. not only of the physical universe but also of the earthly biosphere and the mental, social and abstract forms of existence that emerged from it) is open; there is no absolute developmental limit of the world structure. However, everything given is divided into layers or strata, beginning with the proto-physical world states over the quantum-mechanical, the macrophysical, and biological level up to the social structures of human reality and the abstract structures of the pure symbol systems still going beyond them. -/- The concept of emergence plays an important role in this. However, its development in the history of ideas since the 1920s was unfortunate, because from the outset it was fixed on new individual objects and their properties. In the process, both the processuality of the world and the insight that new structural layers or strata of the world are not represented by individual objects or their properties, but by new types of objects, states, and processes, were lost. This differs from traditional emergence theory, which at first seems inconspicuous, and opens up entirely new approaches and ways of understanding the structural development of the world as a whole. (560 pages, hardcover). (shrink)

The current debate on literary cognitivism in the philosophy of fiction typically assumes that we can rigorously distinguish between fictional and factual, and focuses on the question of whether and how works of fiction can impart propositional knowledge to the reader. In this paper we suggest that this way of framing the debate may be problematic. We argue that works of fiction almost inevitably include a reference to the real world and that – contrary to what is usually assumed – (...) the exchange between fiction and reality is vivid as well as potentially fruitful. We shed a new light on these complex dynamics by building on the metaphors of trade exchange and smuggling between the two worlds. While the current debate exclusively focuses on cognitively relevant goods that “officially” cross the border through “customs”, as it were, we show that exchanges between fiction and reality run deeper. Indeed, as we show, a substantial part of the cognitive impact that we derive from fiction goes “under the table” and is “smuggled” from fiction to reality. As such, it bypasses the audience’s conscious control, which in turn explains the manipulative force that fiction can exert. Smuggling takes place when cognitively relevant contents are passed on to the reader in subliminal ways, as it happens when they imprint implicit biases or prejudices, shift perspectives or subtly modify habits or patterns of behavior. By elaborating on the metaphors of trade exchange and smuggling, we aim at presenting a more comprehensive and nuanced understanding of the relations between fiction and reality and on the impact that imagination has on our real-world beliefs. (shrink)

Every domain-specific ontology must use as a framework some upper-level ontology which describes the most general, domain-independent categories of reality. In the present paper we sketch a new type of upper-level ontology, which is intended to be the basis of a knowledge modelling language GOL (for: 'General Ontological Language'). It turns out that the upper- level ontology underlying standard modelling languages such as KIF, F-Logic and CycL is restricted to the ontology of sets. Set theory has considerable mathematical power and (...) great flexibility as a framework for modelling different sorts of structures. At the same time it has the disadvantage that sets are abstract entities (entities existing outside the realm of time, space and causality), and thus a set-theoretical framework should be supplemented by some other machinery if it is to support applications in the ripe, messy world of concrete objects. In the present paper we partition the entities of the real world into sets and urelements, and then we introduce several new ontological relations between these urelements. In contrast to standard modelling and representation formalisms, the concepts of GOL provide a machinery for representing and analysing such ontologically basic relations. (shrink)

Skeptical theists are seeking for some reasonable solutions to the evidential problem of evil. One of the most fundamental responses of skeptical theism is that the concept of “gratuitous evil”, which cannot be a proof of the absence of God. Therefore, it is not the existence of God that skeptical theism suspects. Instead, skeptical theism contemplates whether the evil in the world really has a “gratuitous” basis. This paper focuses on Peter van Inwagen's “no-minimum claim”. No-minimum claim” stands in opposition (...) to the views that assume that God minimizes the evils that exist in the world in order to achieve justice. “No-minimum claim” acknowledges that these evils still have enormous amounts to people. Thus “no-minimum claim” suggests that the evils experienced in the world are incompatible with the “best of all possible worlds” views or the other explanations of classical theodicy. According to the “no minimum claim”, the reason why the amount of evil in the world still seems so high may be God’s deliberate calculations in effecting the distribution of these evils. In order to reach these calculations, it is not necessary for the amount of evil that God allowed to reflect on the world to be perfectly manifested at the minimum level. The purpose of this paper is to consider the skeptical theism approach within the framework of Peter van Inwagen's “no-minimum claim” and to limit his arguments to an alternative approach to skeptic theism. Our claim is that such view coincides with skeptical theism, but the “no- minimum claim” still has some ambiguities at the point of the limits of evil. From this, we can conclude that the “no minimum claim” has received many objections in the skeptical theism literature and these objections are justified at certain points. (shrink)

Anti-cognitivism is best understood as a challenge to explain how works of fictional narrative can add to our worldly knowledge. One way to respond to this challenge is to argue that works of fictional narrative add to our knowledge by inviting us to explore, in the imagination, the perspectives or points of view of others. In the present paper, I distinguish two readings of this thesis that reflect two very different conceptions of “perspective”: a first understanding focuses on what the (...) world looks like from a subjective point of view. Within this framework, we can distinguish approaches that focus on the subjective character of experience from others that explore the nature of subjectivity. I will argue that both strands can be successful only if they acknowledge the de se character of imagining. The second conception understands perspective as a method of representing. To illustrate it, I will look back to the invention of linear perspective in Renaissance painting. I will argue that the definition of perspective as a rule-guided method or technique can shed new light on the thesis that works of narrative fiction are particularly suited to display other perspectives. (shrink)

The distinction of things in themselves and appearances is an integral part of Kant’s transcendental idealism, yet it has often been met with rather significant hostility. Moreover, what surely has not contributed to the popularity of this Kantian doctrine is that there are, or at least there appear to be, two distinct models, detectable in Kant’s texts, to account for this distinction. Most commonly, these two models are called the “two aspect view” on the one hand and the “two world (...) view” on the other, but it is possible that these labels themselves invite misunderstandings and obscure rather than clarify what Kant had in mind with his distinction. In this paper, I shall first briefly discuss how these two models could be described and labelled in a more suitable manner, namely as the “one composite entity view” and the “two separate objects view”. Subsequently, I will enquire which of the models is pertinent for Kant’s solution to the 3rd antinomy. I will try to show that although the two models appear to be incompatible, it is at least plausible to read Kant as using both of them in this crucial text of his oeuvre. Moreover, Kant’s strategy in solving the freedom problem on the basis of an indirectly realist account of the divine intellect provides the clue to understanding how these seemingly incompatible models can co-exist without forcing Kant into maintaining contradictory claims. (shrink)

Literatur ist ein sehr vielschichtiges und lebendiges Phänomen, das beständig im Wandel ist. So wie sie im Laufe der Jahrhunderte und in den verschiedenen Kulturkreisen unter-schiedliche Formen angenommen und anderen Funktionen gedient hat, liegt es in ihrer Natur, immer wieder neue Ausdrucksformen zu entwickeln, die den sich ändernden Be-dürfnissen und Rahmenbedingungen gerecht werden können. Auch die theoretische Aus-einandersetzung mit der Literatur ist Veränderungen unterworfen, die manchmal wellen-förmige Bewegungen anzunehmen scheinen. Neue Fragestellungen geraten in den Mittel-punkt des Interesses, einzelne Aspekte werden (...) besonders beachtet, während andere in Vergessenheit geraten – um eventuell zu einem späteren Zeitpunkt in neuer Form wieder-aufzutauchen. In der Philosophie der Literatur gilt es seit Längerem als weithin anerkannt, dass der Text die entscheidende Größe sei, und dass die Tatsache, dass an der Produktion und Rezeption von literarischen Kunstwerken Menschen beteiligt sind, die mit diesen Werken Ziele verfolgen und Wünsche und Interessen verwirklichen wollen, ignoriert werden kön-ne. Im vorliegenden Beitrag will ich auf die gegenwärtige Diskussion in der Philosophie der Literatur eingehen und für einen Perspektivenwechsel argumentieren: Um dem Phä-nomen Literatur gerecht zu werden, sollten wir versuchen, es ganzheitlich in das Blickfeld zu bekommen. Literatur ist mehr als bloß Text. Sie ist eine soziale Praxis, die einen festen Stellenwert in unserer Gesellschaft hat und stellt ein Medium dar, in dem wir uns mit an-deren austauschen und auf sie abstimmen können. Mein Hauptaugenmerk liegt auf der Debatte um den kognitiven Gehalt der Literatur, weil hier die negativen Auswirkungen der Verkürzung der vorherrschenden Perspektive besonders augenscheinlich sind. (shrink)

I address the question of whether naturalism can provide adequate means for the scientific study of rules and rule-following behavior. As the term "naturalism" is used in many different ways in the contemporary debate, I will first spell out which version of naturalism I am targeting. Then I will recall a classical argument against naturalism in a version presented by Husserl. In the main part of the paper I will sketch a conception of rule-following behavior that is influenced by Sellars (...) and Haugeland. I will argue that rule-following is an essential part of human nature and insist in the social dimension of rules. Moreover, I will focus on the often overlooked fact that genuine rule-following behavior requires resilience and presupposes an inclination to calibrate one's own behavior to that of the other members of the community. Rule-following, I will argue, is possible only for social creatures who follow shared rules, which in turn presupposes a shared (first-person plural) perspective. This implies, however, that our scientific understanding of human nature has to remain incomplete as long as it does not take this perspective, which prima facie seems alien to it, into account. (shrink)

Among historians of philosophy it is often taken for granted that the “Brentano school” was one of the influential philosophical movements at the end of the nineteenth and the beginning of the twentieth century – but Brentano’s own contributions are often eclipsed by that of his direct students. This invites to reflect on the nature of and the unity within the school. Since Brentano’s conception of a rigorous, scientific philosophy had a strong impact on his students, it has been argued (...) that this conception constitutes a unifying element in an otherwise heterogeneous group. The scope of this article is to shed light on this thesis and to show its limits. I argue for a differentiated view: the Brentano school is best seen not as a compact movement, but as a heterogeneous group of scholars who approached, in a given historical and geographical period, similar topics in very similar ways. (shrink)

The aim of this paper is to show that Priest's modal Meinongianism might benefit from joining forces with two-dimensionalism. For this purpose, I propose a two-dimensional solution to a problem for modal Meinongianism that is posed by Beall, Sauchelli, and Milne, and show that, by taking recourse to two-dimensionalism, divergent intuitions about the question of whether fictional characters might exist can be reconciled. Moreover, two-dimensionalism helps to rebut Kroon's argument to the conclusion that modal Meinongianism cannot rule out the odd (...) claim that some non-existent objects have existence-entailing properties at the actual world. (shrink)

The aim of this article is to provide an account of introspective knowledge concerning visual experiences that is in accordance with the idea of transparent introspection. According to transparent introspection, a person gains knowledge of her own current mental state M solely by paying attention to those aspects of the external world which M is about. In my view, transparent introspection is a promising alternative to inner sense theories. However, it raises the fundamental question why a person who pays attention (...) to something extra-mental should be epistemically justified in holding a belief about something intra-mental. In his Naturalizing the Mind, Fred Dretske solves this problem by conceiving of introspection concerning visual experiences as an inference based on a connecting belief. Although Dretske's account proves defective upon closer inspection, its essence can be salvaged by looking upon introspection as being a game of make-believe. (shrink)

In his seminal paper, ‘Can There Be Vague Objects?’ (1978), Gareth Evans advanced an argument purporting to prove that the idea of indeterminate identity is incoherent. Aware that his argument was incomplete as it stands, Evans added a remark at the end of his paper, in which he explained how the original argument needed to be modified to arrive at an explicit contradiction. This paper aims to develop a modified version of Evans’ original argument, which I argue is more promising (...) than the modification that Evans proposed in his remark. Last, a structurally similar argument against the idea of indeterminate existence is presented. (shrink)

The aim of this paper is to show that introspective beliefs about one’s own current visual experiences are not immediate in the sense that what justifies them does not include other beliefs that the subject in question might possess. The argument will take the following course. First, the author explains the notions of immediacy and truth-sufficiency as they are used here. Second, the author suggests a test to determine whether a given belief lacks immediacy. Third, the author applies this test (...) to a standard case of formation of an introspective belief about one’s own current visual experiences and concludes that the belief in question is neither immediate nor truth-sufficient. Fourth, the author rebuts several objections that might be raised against the argument. (shrink)

In this article I argue that the strong fascination that Wittgenstein has had for artists cannot be explained primarily by the content of his work, and in particular not by his sporadic observation on aesthetics, but rather by stylistic features of his work formal aspects of his writing. Edoardo Paolozzi’s testimony shows that artists often had a feeling of acquaintance or familiarity with the philosopher, which I think is due to stylistic features of his work, such as the colloquial tone (...) in which Wittgenstein shares his observation with the reader, but also the lack of long-winded arguments or explanations. In the concluding part I suggest that we can read Wittgenstein’s artworks of a specific kind: as philosophical works of art. (shrink)

In accordance with the contemporary state of the natural sciences, Wolfgang Sohst here presents an extended ontological model where the process is the first cosmological category, not objects. Her starts with very few primordial categories of becoming that even precede the fundamental concepts of physics and mathematics. Since Democritus, ie. for about 2,400 years, all cultures of European descent rest mainly on the presupposition that substances and their properties provide the inventory of our world. This, however, contradicts the formerly (...) and still today lively intuition (intellectually up to Heraclitus, again in Aristotle and only then resurgent with Hegel) that objects are not the dominating aspect of what we are living in. Rather, the basis of our cosmos is a world process as the result of the complementary relationship of particular objects and their mutual efficiencies. (shrink)

Complex problem solving (CPS) and related topics such as dynamic decision-making (DDM) and complex dynamic control (CDC) represent multifaceted psychological phenomena. In a broad sense, CPS encompasses learning, decision-making, and acting in complex and dynamic situations. Moreover, solutions to problems that people face in such situations are often generated in teams or groups. In turn, this adds another layer of complexity to the situation itself because of the emerging issues that arise from the social dynamics of group interactions. This framing (...) of CPS means that it is not a single construct that can be measured by using a particular type of CPS task (e.g. minimal complex system tests), which is a view taken by the psychometric community. The proposed approach taken here is that because CPS is multifaceted, multiple approaches need to be taken to fully capture and understand what it is and how the different cognitive processes associated with it complement each other. (shrink)

The existence of a Catholic Intellectual Tradition (CIT) is not a given, as arguments contra are in balance with arguments pro. An intellectual tradition consists of a style of thought and of a worldview, as its formal and material modes. The former defines the way knowledge is appropriated, processed, and passed on whereas the latter amounts to its applications to various regions of reality – God, man, morality, society, the Church, etc. A model of the CIT is proposed that consists (...) of principles differentiated by the degree of centrality they have in a topological structure. The paper asserts the existence of a CIT because a non-stipulative, non-trivial, and non-circular case can be made for it. (shrink)