Hans Jonas ranks among a small but expanding group of recent ethicists who have argued that a robust ethical theory must account for human ontological considerations. He is among those who make claims that such considerations issue from biological foundations. In The Phenomenon of Life, he reclaims elements of the Aristotelian biological ontology of the soul while adjusting this ontology to the theory of evolution. The first problem with Aristotelian biological ontology, one suffering from essentialism, is the confrontation with the biological flux of species, presented in the Darwinian theory of natural selection. The dissertation explains that Jonas was correct in his return to Aristotle, insofar as there are elements of human beings that are natural and universal. The task is to follow Jonas by constructing a robust philosophical anthropology. Jonas's philosophical anthropology understands human beings as nature's most magnificent and advanced examples of what he calls "needful freedom." Jonas's argument includes a refutation of reductive materialism and epiphenomenalism, one that leaves the possibilities of the human soul/consciousness and freedom in at least as good a position as offered by Kant. His argument is also an attempt to rescue ontology, human nature, and ethics from the relativism of Heideggerian thought. He does this by replacing Heidegger's concept of "thrown projection" with an idea of "projection" based on biological ontology. With this ontological foundation in place, Jonas's "ethics of the future" sees human beings as the caretakers not only of themselves but of the totality of nature and not simply for anthropocentric reasons. Jonas's philosophical anthropology was incomplete insofar as it lacked an accounting of sexual reproduction, a key element for Jonas's ethical theory where political responsibility is modeled after parenthood. After offering a critique of Jonas's incomplete philosophical anthropology and the gap it leaves for his ethical theory, this dissertation shows that the value of his contribution remains intact. / Philosophy

Pode-se afirmar que a Guilhotina de Hume diz respeito a um conjunto de discussões filosóficas acerca da primazia do ser (Sein) ou do dever-ser (Sollen) ao se fundamentar enunciados de caráter normativo (e, consequentemente, sua validade e aplicação). O foco deste trabalho é analisar a Guilhotina de Hume sob a perspectiva da ontologia fenomenológica (existencial), em que a dicotomia entre dever-ser e ser será redirecionada, em função especificamente da análise ética e jurídica que será concluída, para a dicotomia necessidade/possibilidade, tal como proposta pela própria tradição filosófica ao tratar da análise das modalidades (ser-real/realidade, ser-possível/possibilidade e ser-necessário/necessidade). Inicialmente será mantido que as discussões em torno do dever-ser encontram-se usualmente imbuídas de uma narrativa totalmente dependente do ser-necessário, que na verdade não poderia ser usada para aqueles seres que podem ser diferentes do que são. Ao final será considerado como fundamento originário (Ur-sprung Ab-grund) do ser-jurídico o poder-ser existencial (liberdade), revelado que é através de decisões, dramáticas e quotidianas, que não se restringem às decisões de caráter técnico-sacerdotais. / One might put forward that the Humes Guillotine relates to a set of philosophical discussions about the primacy either of the being (Sein) or of the ought-to (Sollen) in order to ground normative propositions (and, eventually, their validity and enforcement). This work focuses on the analysis of the Humes Guillotine under the perspective of the phenomenological (existential) ontology, in which the dichotomy between the ought-to and the being will be redirected, specifically in light of the ethical and juridical analysis that will be carried out, to the dichotomy necessity/possibility, such as proposed by the philosophical tradition on examining the modalities (being-real/reality, being-possible/possibility and being-necessary/necessity). At the beginning it will be maintained that the discussions over the ought-to are usually embedded with a narrative totally dependent on the being-necessary, which in fact could not be applied to those beings that can be different from what they are. In the end, the existential may-be (freedom) will be considered as the original ground (Ur-sprung Ab-grund) of the being-legal, as reveled through dramatic and everyday decisions, which are not restricted to technical and sacerdotal ones.

Pode-se afirmar que a Guilhotina de Hume diz respeito a um conjunto de discussões filosóficas acerca da primazia do ser (Sein) ou do dever-ser (Sollen) ao se fundamentar enunciados de caráter normativo (e, consequentemente, sua validade e aplicação). O foco deste trabalho é analisar a Guilhotina de Hume sob a perspectiva da ontologia fenomenológica (existencial), em que a dicotomia entre dever-ser e ser será redirecionada, em função especificamente da análise ética e jurídica que será concluída, para a dicotomia necessidade/possibilidade, tal como proposta pela própria tradição filosófica ao tratar da análise das modalidades (ser-real/realidade, ser-possível/possibilidade e ser-necessário/necessidade). Inicialmente será mantido que as discussões em torno do dever-ser encontram-se usualmente imbuídas de uma narrativa totalmente dependente do ser-necessário, que na verdade não poderia ser usada para aqueles seres que podem ser diferentes do que são. Ao final será considerado como fundamento originário (Ur-sprung Ab-grund) do ser-jurídico o poder-ser existencial (liberdade), revelado que é através de decisões, dramáticas e quotidianas, que não se restringem às decisões de caráter técnico-sacerdotais. / One might put forward that the Humes Guillotine relates to a set of philosophical discussions about the primacy either of the being (Sein) or of the ought-to (Sollen) in order to ground normative propositions (and, eventually, their validity and enforcement). This work focuses on the analysis of the Humes Guillotine under the perspective of the phenomenological (existential) ontology, in which the dichotomy between the ought-to and the being will be redirected, specifically in light of the ethical and juridical analysis that will be carried out, to the dichotomy necessity/possibility, such as proposed by the philosophical tradition on examining the modalities (being-real/reality, being-possible/possibility and being-necessary/necessity). At the beginning it will be maintained that the discussions over the ought-to are usually embedded with a narrative totally dependent on the being-necessary, which in fact could not be applied to those beings that can be different from what they are. In the end, the existential may-be (freedom) will be considered as the original ground (Ur-sprung Ab-grund) of the being-legal, as reveled through dramatic and everyday decisions, which are not restricted to technical and sacerdotal ones.