Bartosz Michał Radomski
Affiliation: Ruhr University Bochum
Category: Philosophy
Keywords: Adaptivity, Metabolism, Enactivism, Free-energy Principle, Philosophy of Biology
Date: Thursday 4th of September
Time: 18:00
Location: Room 232 (232)
View the full session: Embodied Cognition
Adaptivity, a capacity to adjust in the face of perturbation, is a prerequisite for cognition. This assumption underlies prominent modelling approaches such as enactivism (e.g., Di Paolo 2005; Thompson 2007) and active inference (Parr, Pezzulo, and Friston 2022). Yet, despite its central role, adaptivity remains conceptually underdeveloped in these frameworks. My aim is to bring adaptivity into the philosophical spotlight and argue that it presents a distinct set of conceptual challenges that require independent analysis.
The Trouble with Adaptivity
Defining adaptivity has proven to be surprisingly tricky and elusive. Enactivists equate adaptivity with control, monitoring, and regulation (Di Paolo, Thompson, and Beer, 2022) but do not explain how these traditionally representationalist terms align with their self-declared anti-representational stance (Villalobos, 2013). Nor do they clarify how adaptivity supports the strong life-mind continuity thesis: the idea that cognition and life are share a common set of organisational principles (Godfrey-Smith 1994). Adaptivity has a hard time finding a home within enactivism.
Free-energy theorists have encountered a different but equally serious problem. They have come to recognise that their account of adaptivity in terms of active inference risks being both circular and trivial: adaptive systems are defined as those that engage in active inference, yet any ‘thing’ that persists over time, such as a pebble on a beach, can be described as engaging in active inference and, consequently, treated as an adaptive system (van Es and Kirchhoff, 2021).
Overall, the enactive and free-energy models of cognition serve as cautionary tales. Without a clear and principled definition of adaptivity, our theories may end up trivially applicable (even to a pebble) or internally incoherent with other modelling assumptions (representational mechanisms of non-representational processes). Insights from models of cognition point to the need for a more rigorous account of adaptivity.
Three Puzzles of Adaptivity
A rigorous definition of adaptivity should address three core puzzles: 1. The Puzzle of Identity: Who or what is adjusting to what? 2. The Puzzle of Norms: What norms guide these adjustments? 3. The Puzzle of Scope: What phenomena does adaptivity apply to? These questions touch on foundational issues that any account of adaptivity should address. Otherwise, our attribution of adaptivity will be arbitrary, blurring the distinction between living systems that adapt their behaviour and physical systems such as pebbles that “adapt” their surface or rivers that “adapt” their flow. The existing models that assume adaptivity (e.g., “adaptive active inference”, Kirchhoff, Parr, et al. 2018) could be scored based on how well they resolve these puzzles. In addition, these puzzles could be used as a useful heuristic or a benchmark for assessing the new modelling approaches.
The Solution: Metabolism as the Ground of Adaptivity
My proposed solution is that adaptivity is contingently grounded in metabolism: the self-sustaining network of material and energetic exchanges. When adaptivity is anchored in metabolism, the three puzzles receive natural answers: • Identity becomes metabolic identity. The adaptive system is the metabolic organisation itself. • Normativity is grounded in metabolic need. Adaptive adjustments are successful when they maintain the conditions for continued metabolic functioning. • Scope encompasses normatively guided responses to actual or anticipated changes in the metabolic organisation. This metabolic account provides a principled way to distinguish genuine adaptivity from mere persistence. A pebble on a beach undergoes mere structural adjustments. Genuine adaptivity has an ineliminable existential stake: without successful metabolic regulation, the system ceases to exist. By grounding adaptivity in metabolism, this framework avoids the pitfalls of incoherence and triviality found in existing models. It simultaneously avoids neurocentrism: adaptivity becomes a basal biological phenomenon, akin to respiration or digestion, common to all life forms, not just those with neural systems. This property makes it attractive for minimal modelling approaches that see cognition at the basal level of living organisation.
The Origin of Adaptivity: A Diachronic Perspective
By grounding adaptivity in metabolism, we are also in a more natural position to address an issue that has, to my knowledge, not been addressed in philosophy of cognitive science at all: namely, the origin of adaptivity. How did adaptivity emerge in evolutionary history? This question has an incredible potential to inform us about the conceptual issues surrounding the definitions of life and cognition. Adaptivity is hypothesised to have evolved from metabolism following the emergence of early forms of energy storage (Boden 1999). Before this, metabolic adjustments would have been driven by environmental factors as day-night cycles and water circulation in shallow seas (Frenkel-Pinter et al. 2021; Runnels et al. 2018). On this interpretation, the early forms of adaptivity relied on stored excess energy to dampen variability and mitigate the effects of perturbations in their highly cyclical environments. This historical interpretation grounds seemingly agential characteristics of adaptivity in non-cognitive physical properties. For instance, selectivity can be seen as rooted in the selective chemistry of water, which underlies most metabolic processes. In this way selectivity can be explained naturalistically without invoking an inward self that ‘chooses’ adjustments.
Implications Beyond Cognitive Science
A rigorous definition of adaptivity has implications beyond the philosophy of mind. This new conceptual approach for understanding adaptivity, initially developed for models of cognition, can reshape key debates in the philosophy of biology regarding the definition of life and the role of organisms in evolutionary processes. More precisely, it provides a fresh perspective on the role of adaptivity in shaping organism-niche relationships and driving evolutionary changes, which is a very topical issue in the philosophy of biology. A central question in evolutionary theory is whether adaptive changes over generations are shaped by the adaptive activity of organisms themselves. Some theorists (e.g., Walsh 2015) argue that organisms play a direct causal role in shaping evolutionary outcomes, while others (e.g., Hoffmann and Parsons 1997) maintain that environmental selection alone drives evolutionary change. My framework can put these opposing views in dialogue without falling into reductionist extremes. Adaptive behaviour becomes a causal factor in evolution, but only within the constraints imposed by metabolic organisation and environmental pressures.