Embodied Cognition Across Four Evolutionary Transitions in Bodily Organisation

Embodied cognition, a research programme that is standardly presented as a corrective to classical cognitive science, insists that brain, body, and environment must be understood together if cognition is to be explained adequately. This paper argues for the stronger claim that cognition has always been an embodied phenomenon, because embodied cognition was the first kind of cognition to evolve. To support this, the paper traces the evolution of cognition across four major transitions in morpho-anatomical organisation: from prokaryotes to eukaryotic protists, from unicellular eukaryotes to multicellular eumetazoans, from diffuse nerve net metazoans to centralised nervous system metazoans, and from transient tool use in animals to the co-evolved incorporation of culturally transmitted artefacts in humans. At the prokaryotic level, cognition is realised through a form of total embodiment, in which cognitive capacities are inseparable from the body that realises and exercises them. Each successive transition expands the range, flexibility, and temporal depth of cognition while preserving its constitutive dependence on bodily organisation. The fourth transition mirrors the first. At the human level, there is no adequate account of present bodily organisation that is separable from the cultural-tool extensions with which it has co-evolved.