我们能够获得那些可能性或必然性的知识吗?--以威廉姆森的观点为契机

Can We Acquire Knowledge of Those Possibilities or Necessities?: Talk from Williamson’s View

模态知识论的核心问题是:"我们如何证成或知道那些仅仅属于可能性(mere possibility)的宣称,与那些既非逻辑亦非数学的必然性宣称?"对于这个问题,威廉姆森论证并主张:由于每一类的模态宣称都逻辑上等价于某一类的反事实条件句宣称,因而日常透过"想象模拟"去评估反事实条件句的认知能力也就给了我们认知形而上学模态性的能力。威廉姆森并且认为,有些这样得来的反事实条件句知识和模态知识,既非先验,亦非后验,应被归属为第三类的"椅验知识"(armchair thinking)。作者们认为威廉姆森的理论虽大体上可信,但仍至少有九个问题需要进一步探讨。

The central issue of modal epistemology is: how can we come to know, or how can we be justified in believing, those claims of metaphysical modality that are either about mere possibilities or about necessities that are neither logical nor mathematical? Williamson’s reply to this question is: since each claim of metaphysical modality is logical equivalent to some claim of counterfactual conditionals, our ordinary cognitive capacity to handle counterfactual conditionals, be what Williamson calls the "imaginative simulation" process, carries with it the cognitive capacity to handle metaphysical modality. Williamson also thinks that a significant part of the knowledge that we obtain by the imaginative simulation process is neither a priori nor a posteriori, but armchair knowledge. Though feeling that it has some prima facie plausibility, the authors still thinks that Williamson account needs to be investigated in details.