Abstract

The paper starts by recalling the ordinary and etymological sense of the word “robustness”, for placing it then in the context of the current systemic view. Then I focus discussion on systems robustness in the paradigmatic case of living organisms. We discover that the notion of robustness is closely linked, in the case of organism, with the notion of difference, given that organisms arise precisely by a differentiation process. So, in order to understand the ontology of robustness, we need to explore the ontology of difference; and in order to do so, we must distinguish between constitutive and comparative difference. Then I deal with the problem of unity of the constitutive differences: I wonder if it is possible to unify the many differences that an organism exhibits in a single difference. It is an important question, given that unity is one of most essential characteristics of the organism. And the answer to this question raises immediately a query for the intelligibility of this final and unique constitutive difference. Such intellibility is possible thanks to the formal nature of the final difference, but it requires also a pluralistic approach. Besides that, we have to sketch the ontological and epistemological relationships between difference, identity and similarity, which will be crucial for intelligibility of the difference, since according to a certain tradition, intelligibility depends on identity.