Christian Carbonell
Affiliation: Universitat de València
Category: Philosophy
Keywords: Philosophy of Action, Philosophy of Neuroscience, Epistemology, Proprioception, Deafferentation
Date: Wednesday 3rd of September
Time: 18:00
Location: Room 232 (232)
View the full session: Self-Knowledge
According to a longstanding tradition in action theory, intentional and unintentional actions differ in that the former involve so-called ‘practical knowledge’ (Anscombe [1957] 2000; Gorr & Horgan 1982; Hampshire 1983; Kenny 1976; Makin 2024; Pavese 2022; Valaris 2022; Wolfson 2012):
Practical Knowledge: For any subject, S, and any action, ϕ, S cannot ϕ intentionally unless S knows that they are ϕ-ing
This condition is often derived from our intuitions about cases. For instance, if Bernie drinks a mix of petrol and tonic (Williams 1981), while falsely believing that it is gin and tonic, there is something intuitively odd in saying that he drinks it on purpose rather than by mistake. Other times, however, intuition pulls us towards the opposite direction. Setiya’s (2008, 2012) ‘fist-clenching’ case seems to be one of those times:
Here, the portrayed subject appears to clench his fist intentionally. After all, their hand is no longer paralysed, and so they can move it as anyone can. Yet, while they truly believe that they are clenching their fist, this belief seems unjustified and does not amount to knowledge. Against Practical Knowledge, this suggests that someone can do something intentionally without knowing that they are doing it. In this talk, I contend that this case lacks empirical support. I begin by arguing that the subject’s belief that they are clenching their fist may not arise from irrational optimism. Instead, as Beddor and Pavese (2022) suggest, they may know so through proprioception. In effect, proprioceptive receptors collect real-time data about the subject’s bodily movements and the relative positions of their body’s parts in space (Longo et al. 2010). Thus, when a neurologically healthy subject moves their body in a particular way, they become proprioceptively aware that such bodily movement is occurring. In turn, this awareness of the body is not had from an utterly impersonal perspective, as if the movement occurred in some anonymous object among others. Nor is the body experienced as alien, as happens in cases of somatoparaphrenia (Feinberg and Venneri 2014; Gandola et al. 2012). Quite the contrary, such awareness appears to be imbued with a distinct ‘sense of ownership’ (Gallagher 2000: 15), representing the movement as occurring specifically within the subject’s own body (Brewer 1995; Evans 1982; Serrahima 2024; Verdejo 2023). Simultaneously, when one such subject moves their body, they also become aware of the bodily movement under a ‘sense of agency’ (Gallagher 2000: 15), representing it as a movement that they are actively generating. In fact, clinical studies demonstrate that neurologically healthy individuals are significantly accurate at recognising their own voluntary hand movements during spatial and temporal tasks of agency discrimination (Fourneret et al. 2002; Farrer et al 2002), reaching accuracy rates of up to 96% in some experiments (Baslev et al. 2007). Importantly, this accuracy appears to rely on the capacity to proprioceptively feel spatio-temporal congruences between bodily movements and the content of those intentions that produced them (Wolpert et al. 1995). Thus, these considerations strongly suggest that, mid-clenching, our subject must be proprioceptively well-positioned to acquire practical knowledge to the effect that they are clenching their fist. At this point, however, one could turn the screw and propose a version of Setiya’s case where the subject lacks proprioception. Here is one such variant adapted from Carter and Shepherd (2023b: 966, fn.18):
While Carter and Shepherd conclude that the patient clenches his fist intentionally without knowing that they are doing it, I object that this conclusion also lacks empirical support. My argument starts with the thought that intentional action requires control (Carter & Shepherd 2023ab; Gibbons 2001; Mele & Moser 1994; Pavese 2021bc; Piñeros-Glasscock 2020; Shepherd 2021). On any plausible account, whether an action is under a subject’s control seems to depend partly on whether the subject can successfully monitor and adjust their behaviour so as to ϕ:
Again, as psychological data suggest, I argue that the patient from Deafferentation cannot meet this condition precisely because they are not visually guiding their action. In effect, unlike neurologically healthy subjects, deafferented individuals have impaired proprioceptive capacities, lacking bodily sensations from the neck down in severe cases. This impairment, in turn, appears to coincide with the loss of the kind of motor control that is required for performing intentional bodily actions. Arguably, since proprioception plays a central role in the monitoring of bodily movement (González-Grandón et al. 2021), deafferented subjects become unable to suitably adjust their movement in relation to the intended goal, generally leading to erratic bodily behaviour (Cole 1991: 16). Interestingly, however, deafferented subjects have been shown to compensate for this motor impairment through observational attention (Blouin et al. 1993; Cole & Paillard 1995; Ghez et al. 1990, 1995; Renault et al. 2018; Wong 2018). By visually monitoring their bodily behaviour while it unfolds, deafferented subjects manage to successfully direct and adjust their movements in the way required for intentional action. Thus, while these findings are compatible with a deafferented patient clenching their fist simpliciter without relying on visual support, they suggest against Carter and Shepherd the claim that such a patient would not be able to clench their fist intentionally without watching their hand.