Jonny Lee

Recent advances in plant biology suggest that plants engage in complex behaviours once thought to require nervous systems. This article surveys the empirical foundations of plant cognition, covering research on goal‐directed movement, decision‐making, anticipatory behaviour, communication, phytoacoustics, and plant neurobiology. In addition, we examine evidence for systemic signalling and anaesthesia in plants, alongside parallels and contrasts with animal cognition. These findings indicate that cognition may not be restricted to neural organisms, challenging conventional boundaries of mind. Building on this empirical base, we explore the philosophical and ethical implications of attributing cognition to plants. The discussion engages classic debates about other minds, functionalism, multiple realisability, and the possibility of plant sentience. Even if plant sentience remains speculative, their cognitive complexity raises broader questions about ecological value, precautionary concern, and the scope of moral consideration. Taken together, these discussions highlight how empirical discoveries in plant biology intersect with enduring philosophical questions about mind, intelligence, and moral status. A companion article, Plant Cognition—A Methodological Primer, provides the necessary theoretical and methodological background, whereas this piece focuses on evidence and implications.

Part I: What counts as cognition, and how can it be studied in organisms without nervous systems? The emerging field of plant cognition confronts these questions by integrating philosophy, plant science and comparative psychology. This article provides a methodological primer on the field. We first survey major theoretical approaches—computationalist and representationalist, radical embodied, and behaviour‐first—and consider how they might be integrated. We then examine methodological strategies, from comparative experimental paradigms to the role of philosophy in clarifying concepts and guiding research design. Finally, we address key epistemic challenges, including replicability, anthropomorphism and confirmation bias. Taken together, these discussions establish a conceptual and methodological foundation for plant cognition research. A companion article, Plant Cognition—An Empirical Primer, complements this survey by reviewing the empirical evidence and its philosophical implications.

The mechanistic model depicts scientific explanations as involving the discovery of multi-level, organized components that constitute a target phenomenon. Meanwhile, sensorimotor enactivism purports to offer a scientifically informed account of perceptual experience as a skill-laden interactive relationship, constitutively involving both perceiver and world, rather than as an agent-bound representation of the world. Insofar as sensorimotor enactivism identifies an empirically tractable phenomenon – skillful agent-world interaction – and mechanistic explanation establishes the subpersonal components of this phenomenon, the two approaches allow for a fruitful division of labor in investigating perceptual experience. On closer inspection, however, two challenges arise. First, the “representation challenge” arises because promising attempts to set out implementational details of our sensorimotor interaction with the world implicate cognitive representations, creating tension with sensorimotor enactivism’s nonrepresentational commitments. Second, the “reconstitution challenge” arises when mechanistic explanation not only uncovers the components of some established phenomenon but plays a role in “reconstituting” this phenomenon. This means that, through investigating mechanisms, perceptual experience may be reconceived such that its constituents are wholly organism-bound. We explore both challenges to the compatibility of mechanism and sensorimotor enactivism and examine possible solutions. The result is a clearer understanding of the tensions and opportunities for learning between the frameworks.

The mechanism underlying action potentials is routinely used to explicate the mechanistic model of explanation in the philosophy of science. However, characterisations of action potentials often fixate on neurons, mentioning plant cells in passing or ignoring them entirely. The plant sciences are also prone to neglecting non-neuronal action potentials and their role in plant biology. This oversight is significant because plant action potentials bear instructive similarities to those generated by neurons. This paper helps correct the imbalance in representations of action potentials by offering an overview of the mechanism for plant action potentials and highlighting their similarity to those in neurons. Furthermore, it affirms the role of plant action potentials in discovering the evolution and function of mechanisms of action potentials more broadly. We stress the potential of plants for producing generalisations about action potentials and the possible role of plants as experimental organisms.

The structural representation (S-representation) account provides an increasingly popular way of understanding the role and value of representation in cognitive science. Yet critics remain unconvinced that the account has the resources to rescue representationalism. This paper reviews problems faced by the S-representation account. In doing so, it offers a novel taxonomy that divides objections into two broad camps that ought to be disambiguated: ‘conceptual’ and ‘empirical’. It further shows how these objections can be met, bolstering existing responses in the literature with novel solutions, thus strengthening the S-representation account. Finally, this paper suggests that the types of objections identified provide a generalisable taxonomy for a better understanding of any version of anti-representationalism. Thus, this review is of value to the representation debate more broadly.

There is growing evidence that plants possess abilities associated with cognition, such as decision-making, anticipation and learning. And yet, the cognitive status of plants continues to be contested. Among the threats to plant cognitive status is the ‘Representation Demarcation Challenge’ which points to the absence of a seemingly defining aspect of cognition, namely, computation over representation with non-derived content. Defenders of plant cognition may appeal to post-cognitivist perspectives, such as enactivism, which challenge the assumptions of the Representation Demarcation Challenge. This points to an impasse in the debate over plant cognition as it collapses into perennial disagreements over the best way to conceptualise the very nature of cognition. I propose a path that allows us to bypass this quagmire by reconceiving the question of what is cognitive about ‘plant cognition’ in terms of a quest to map the many possible adaptive capacities and behaviours more-or-less associated with cognition, alongside their underlying processes and mechanisms. In turn, we can examine the degrees of similarity between plants and more paradigmatically cognitive creatures. The ‘piecemeal approach’ thus shifts attention away from the abstract and dichotomous question of whether plants are cognitive and towards a series of more precise questions about the many ways and extent to which plants possess features associated with cognition. Ultimately, I suggest, the value of viewing plants through a cognitive lens may lie less in determining whether they are bona fide cognitive creatures and more in guiding research into concrete abilities and their underlying causes.

Enactivism advances an understanding of cognition rooted in the dynamic interaction between an embodied agent and their environment, whilst new mechanism suggests that cognition is explained by uncovering the organised components underlying cognitive capacities. On the face of it, the mechanistic model’s emphasis on localisable and decomposable mechanisms, often neural in nature, runs contrary to the enactivist ethos. Despite appearances, this paper argues that mechanistic explanations of cognition, being neither narrow nor reductive, and compatible with plausible iterations of ideas like emergence and downward causation, are congruent with enactivism. Attention to enactivist ideas, moreover, may serve as a heuristic for mechanistic investigations of cognition. Nevertheless, I show how enactivism and approaches that prioritise mechanistic modelling may diverge in starting assumptions about the nature of cognitive phenomena, such as where the constitutive boundaries of cognition lie.