The study of presumptions has intensified in argumentation theory over the last years. Although scholars put forward different accounts, they mostly agree that presumptions can be studied in deliberative and epistemic contexts, have distinct contextual functions (guiding decisions vs. acquiring information), and promote different kinds of goals (non-epistemic vs. epistemic). Accordingly, there are “practical” and “cognitive” presumptions. In this paper, I show that the differences between practical and cognitive presumptions go far beyond contextual considerations. The central aim is to explore Nicholas Rescher’s contention that both types of presumptions have a closely analogous pragmatic function, i.e., that practical and cognitive presumptions are made to avoid greater harm in circumstances of epistemic uncertainty. By comparing schemes of practical and cognitive reasoning, I show that Rescher’s contention requires qualifications. Moreover, not only do practical and cognitive presumptions have distinct pragmatic functions, but they also perform different dialogical functions (enabling progress vs. preventing regress) and, in some circumstances, cannot be defeated by the same kinds of evidence. Hence, I conclude that the two classes of presumptions merit distinct treatment in argumentation theory.

中文翻译：

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实践推定与认知推定的区别

在过去的几年里，论证理论中的推定研究得到了加强。尽管学者们提出了不同的解释，但他们大多同意推定可以在审议和认知语境中进行研究，具有不同的语境功能​​（指导决策与获取信息），并促进不同类型的目标（非认知与认知）。因此，存在“实际”和“认知”假设。在本文中，我展示了实践假设和认知假设之间的差异远远超出了上下文考虑。中心目标是探讨 Nicholas Rescher 的论点，即两种类型的假设都具有非常相似的语用功能，即，做出实践和认知假设是为了避免在认知不确定的情况下造成更大的伤害。通过比较实践推理和认知推理的方案，我表明 Rescher 的论点需要资格。此外，实践假设和认知假设不仅具有不同的语用功能，而且还具有不同的对话功能（促进进步与防止倒退），并且在某些情况下不能被同类证据打败。因此，我得出结论，这两类推定在论证理论中值得区别对待。