Ontogenesis, Organisation, and Organismal Agency

At first sight, the empirical study of ontogenesis and the theoretical study of organismal agency seem to have little in common. In this chapter, I discuss why this initial impression is incorrect. First of all, ontogenesis and agency are indirectly connected at the level of the whole organism, because they are co-dependent on the peculiar organisation that characterises living systems. While ontogenesis is constrained by its own requirement to maintain living organisation in the form of organisational closure throughout the lifecycle, agency is grounded in the same phenomenon of organisational continuity. Secondly, cellular agency contributes more directly to various important processes of multicellular development in organisms with multiple levels of organisation. This leads to a view of ontogenesis that emphasises agency and variation in the underlying cellular dynamics and focuses on stability and reproducibility of ontogenetic processes as its main explanatory targets. I examine how these insights can help us bridge the explanatory gap between reductionist mechanistic empirical approaches and theoretical considerations regarding the organisation of an organism as a whole. I conclude that the two approaches are best used in a complementary manner. Only by placing ontogenetic mechanisms within the larger context of the evolving lifecycle can we arrive at an adequate understanding of their functionality and evolution.