The aim of this paper is two-fold: first, it is intended to articulate theses that are often assessed independently, thus showing that a strong version of epistemological disjunctivism about perceptual knowledge implies a transformative conception of rationality. This entails that individuals in skeptical scenarios could not entertain rational thoughts about their environment, for they would fail to have perceptual states. The secondary aim is to show that this consequence is not a sufficient reason to abandon the variety of disjunctivism presented. (...) The argument for this claim depends on the assessment of rationality attributions to subjects in plausible cases of illusion and some clinical cases of hallucination. RESUMO Este artigo tem dois objetivos: primeiramente, pretende-se articular teses que são frequentemente avaliadas independentemente, mostrando com isso que uma versão robusta do disjuntivismo epistemológico sobre conhecimento perceptual implica uma concepção transformativa da racionalidade. Uma consequência disso é que indivíduos em cenários céticos não poderiam entreter pensamentos racionais sobre o ambiente em que habitam, pois eles não possuiriam estados perceptuais. Em segundo lugar, argumenta-se que a consequência delineada acima não é uma razão suficiente para rejeitar o disjuntivismo tal como apresentado. Esse argumento depende da avaliação de atribuições de racionalidade a indivíduos em casos plausíveis de ilusão e em alguns casos clínicos de alucinação. (shrink)

Are we perhaps in the "matrix", or anyway, victims of perfect and permanent computer simulation? No. The most convincing—and shortest—version of Putnam's argument against the possibility of our eternal envattment is due to Crispin Wright (1994). It avoids most of the misunderstandings that have been elicited by Putnam's original presentation of the argument in "Reason, Truth and History" (1981). But it is still open to the charge of question-begging. True enough, the premisses of the argument (disquotation and externalism) can (...) be formulated and defended without presupposing external objects whose existence appears doubtful in the light of the very skeptical scenario which Putnam wants to repudiate. However, the argument is only valid if we add an extra premiss as to the existence of some external objects. In order to avoid circularity, we should run the argument with external objects which must exist even if we are brains in a vat, e.g. with computers rather than with trees. As long as the skeptic is engaged in a discussion of the brain-in-a-vat scenario, she should neither deny the existence of computers nor the existence of causal relations; for if she does, she is in fact denying that we are brains in a vat. (shrink)

Nick Bostrom’s recently patched ‘‘simulation argument’’ (Bostrom in Philos Q 53:243–255, 2003; Bos- trom and Kulczycki in Analysis 71:54–61, 2011) purports to demonstrate the probability that we ‘‘live’’ now in an ‘‘ancestor simulation’’—that is as a simulation of a period prior to that in which a civilization more advanced than our own—‘‘post-human’’—becomes able to simulate such a state of affairs as ours. As such simulations under consid- eration resemble ‘‘brains in vats’’ (BIVs) and may appear open to similar objections, the (...) paper begins by reviewing objections to BIV-type proposals, specifically those due a presumed mad envatter. In counter example, we explore the motivating rationale behind current work in the development of psychologically realistic social simula- tions. Further concerns about rendering human cognition in a computational medium are confronted through review of current dynamic systems models of cognitive agency. In these models, aspects of the human condition are repro- duced that may in other forms be considered incomputable, i.e., political voice, predictive planning, and consciousness. The paper then argues that simulations afford a unique potential to secure a post-human future, and may be nec- essary for a pre-post-human civilization like our own to achieve and to maintain a post-human situation. Long-s- tanding philosophical interest in tools of this nature for Aristotle’s ‘‘statesman’’ and more recently for E.O. Wilson in the 1990s is observed. Self-extinction-level threats from State and individual levels of organization are compared, and a likely dependence on large-scale psychologically realistic simulations to get past self-extinction-level threats is projected. In the end, Bostrom’s basic argument for the conviction that we exist now in a simulation is reaffirmed. (shrink)