盖梯尔问题、认知运气与可能世界——诺齐克敏感性理论对怀疑主义的回应

Gettier problem, epistemic luck and possible worlds:Response of Nozickian sensitivity theory to skepticism

在对知识成立条件的探索中,运气对知识的摧毁作用逐渐受到人们的关注。为了排除这种与知识不相容的认知运气,诺齐克从可能世界理论出发提出敏感性理论,主张只有当认知主体的信念状态能够对命题的真值进行追踪的时候其真信念才能算作知识。敏感性理论成功解决了诸多盖梯尔反例,深化了人们对知识的理解与把握。面对怀疑主义的挑战,敏感性理论一方面承认自己无法证明怀疑主义者的假说是假的,另一方面则在此基础上继续说明人类的日常知识何以可能。然而在对怀疑主义的处理过程中,敏感性理论由于拒斥了知识封闭原则从而受到诸多责难,而敏感性是否是真信念成为知识的充分必要条件也受到克里普克等哲学家的质疑。

In the exploration of the conditions for knowledge, people gradually recognize the role ofknowledge-destroying luck. In order to preclude the epistemic luck which is incompatible with knowledge, RobertNozick puts forward the sensitivity theory from the perspective of possible worlds, advocating that a true belief couldbe seen as knowledge if and only if the cognitive agent’s belief statuses towards proposition p could track the truthvalue of p. The sensitivity theory manages to deal with many Gettier-like counterexamples, greatly deepening andenhancing our understanding and comprehension of the thesis of knowledge. Confronted with the challenges fromskepticism, the sensitivity theory on the one hand acknowledges that it can’t falsify the hypotheses of skepticism; on theother hand it continues to explain why we could still retain almost all of our ordinary knowledge. However, in itstreatment of skepticism, the sensitivity theory controversially refutes the epistemic closure principle, which used to beregarded as an evidently right principle. What’s more, according to philosophers such as Saul Kripke, it still remains aproblem whether the conditions of the sensitivity theory are individually necessary and jointly sufficient for a true beliefto constitute knowledge.