Abstract

Biological individuals are usually defined by evolutionists through a reference to natural selection. This article looks for a concept of individuality that would hold at the same time for organisms and for communities or ecosystems, the latter being unaffected by natural selection. In the wake of Simon’s notion of “quasi-independence,” I elaborate a concept of “weak individuality” defined by probabilistic connections between sub-entities, read off our knowledge of their interactions. This formal scheme of connections allows one to infer what are the individuals in the domain addressed by the theory of the interactions. The article argues that if ecosystems do not have strong individuality, they still possess a weak individuality, ecological theories providing the values of the variables in the formula for individuality.