On the Differences Between Practical and Cognitive Presumptions

Abstract

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.

Putting the ‘presumption’ back in the ‘presumption of innocence’

“…Cognitive presumptions are just those epistemic presumptions that are part of our cognitive toolkit in figuring out the way things are and acquiring true, justified beliefs about them (Bodlović, 2020: 266, 2021: 289–290). As Bodlović (2020: 258) argues, cognitive presumptions are ‘typically used in the context of [epistemic] inquiry’, in the promotion of epistemic goals (ie, finding out truth) (Rescher, 2006: 71).…”

“…Second, consider a different epistemic inquiry where the question is ‘Where is Andy's cat?’ When Andy (who has lost his pet cat) looks outside his window and sees a cat in the tree that looks identical to his own missing cat, he forms a presumptive view that this cat is his: ‘although ‘Andy's cat is in the tree’ is uncertain from a sceptical viewpoint, Andy acts on it by relying on his senses and by using it as a tentative premise in reasoning’ (Bodlović, 2021: 289). In each example, particular attention should be given to how q , being the ‘most plausible truth candidate’, is supported by evidence: the mainstream scientific opinion is evidence of ‘the Earth is round’, whereas Andy's visual perception and memory are evidence of ‘Andy's cat is in the tree’(Bodlović, 2021: 301; Rescher, 2003: 81–100).…”

“…Second, consider a different epistemic inquiry where the question is ‘Where is Andy's cat?’ When Andy (who has lost his pet cat) looks outside his window and sees a cat in the tree that looks identical to his own missing cat, he forms a presumptive view that this cat is his: ‘although ‘Andy's cat is in the tree’ is uncertain from a sceptical viewpoint, Andy acts on it by relying on his senses and by using it as a tentative premise in reasoning’ (Bodlović, 2021: 289). In each example, particular attention should be given to how q , being the ‘most plausible truth candidate’, is supported by evidence: the mainstream scientific opinion is evidence of ‘the Earth is round’, whereas Andy's visual perception and memory are evidence of ‘Andy's cat is in the tree’(Bodlović, 2021: 301; Rescher, 2003: 81–100). See now that cognitive presumptions that- q are evidentiary in the same way that Sceptics hold ‘true’ presumptions to be: 20 in both cases, ‘a standard epistemic source … such as sense-perception, memory, testimony, expert-testimony, or common knowledge’ (Bodlović, 2021: 301) provides the evidentiary grounds for q as the ‘most plausible truth candidate’ (thereby enabling a cognitive presumption that- q ).…”

“…In each example, particular attention should be given to how q , being the ‘most plausible truth candidate’, is supported by evidence: the mainstream scientific opinion is evidence of ‘the Earth is round’, whereas Andy's visual perception and memory are evidence of ‘Andy's cat is in the tree’(Bodlović, 2021: 301; Rescher, 2003: 81–100). See now that cognitive presumptions that- q are evidentiary in the same way that Sceptics hold ‘true’ presumptions to be: 20 in both cases, ‘a standard epistemic source … such as sense-perception, memory, testimony, expert-testimony, or common knowledge’ (Bodlović, 2021: 301) provides the evidentiary grounds for q as the ‘most plausible truth candidate’ (thereby enabling a cognitive presumption that- q ).…”

“…Many Sceptics have refused to see that the PoI is a presumption because they have latched onto a narrow, evidentiary understanding of ‘presumption’ as a factual inference in the form, ‘if p then pres q ’ (similar to the evidentiary presumption that a person is presumed deceased if she has been missing for over seven years) (for example, Weigend, 2013: 193–194). Argumentation theory shows us that presumptions are a heterogenous device (Bodlović, 2019, 2020; Gama, 2017; Godden and Walton, 2007; Lewiński 2017), and that the PoI can be seen as a non-evidentiary type of presumption (but a presumption nonetheless)—what Nicholas Rescher (2006: 29) and Petar Bodlović (2021) term a ‘practical presumption’. 2 Benefitting from argumentation theory's more nuanced understanding of presumptions, I demonstrate that the PoI can be a (type of) presumption—specifically, a practical presumption with a non-evidentiary goal: of avoiding the greater harm of wrongfully convicting the innocent as opposed to falsely acquitting the guilty (Bodlović, 2019: 582, 2020; Ullmann-Margalit, 1983: 155).…”