The project From Teleology to Plasticity and Back develops a new philosophical account of teleology in biology from a Biological Autonomy Theory (TBA) perspective, arguing that plasticity is an essential, hitherto overlooked component of organismal goal-directedness. While organism-centred approaches in biology increasingly portray organisms as active participants in development and evolution, current philosophical theories struggle to explain how organisms themselves can modify their own goals. The project thus raises the question: how can teleology be reconceptualised so that organisms are understood not only as maintaining their goals, but as transforming them, across both ontogenetic and evolutionary times and scales? Its thesis is that plasticity, understood as the organism’s capacity to receive, give, and shape its own form in relation to the environment, is a necessary yet hitherto overlooked component of organismal goal-directedness, which any naturalistic theory of biological teleology should account for. The Theory of Biological Autonomy (TBA), the most robust causal account of biological goal-directedness currently available, must accordingly be revised, since its success over developmental and evolutionary scales is limited by a commitment to goal-fixity and invariance.

Moving from and within the TBA, the project pursues a plasticity-inclusive reconceptualisation of teleology through three interconnected theoretical contributions. Two novel desiderata for naturalistic teleology are first identified and tested: an “identity desideratum”, precondition for naturalisation, and a “plasticity desideratum”, necessary to account for the specificity and changeability of biological goals. Measured against these desiderata, the TBA satisfies the identity desideratum but falls short of the plasticity one, remaining committed to a goal-invariance that cannot account for how organisms modify their own goals. Closing this gap is the central, constructive task of the thesis: drawing on recent work in the Extended Evolutionary Synthesis (EES), eco-evo-devo, and the ecological approach to agency, the project constructs a positive account of plasticity-inclusive teleology from a TBA perspective, integrating resources from multiple frameworks: the notion of reproducer, extended inheritance, plasticity-first evolution, facilitated variation, heritable physiological exploration, transgenerational plasticity, and developmental exaptation. Taking plasticity into account is necessary to determine the coordinates of a good naturalistic teleology, to strengthen and expand the TBA, and thus to offer the basis of a TBA-EES bridge, clarifying on organisational bases the evolutionary role of organisms as purposive agents, for instance in actively biassing variation towards adaptivity, reconstructing it across generations, and initiating forms of plasticity-first evolution. In this way, the project strengthens the philosophical foundations for the active causal role of organisms in adaptively shaping the evolutionary process.