Abstract
Factive scientific understanding is the thesis that scientific theories and models provide understanding insofar as they are based on facts. Because science heavily relies on various simplifications, it has been argued that the facticity condition is too strong and should be abandoned.
In this paper I present a general model of a metabolic pathway regulation by feedback inhibition in order to argue for two things. First, while the critics of the facticity condition have drawn on the notion of idealization to show that the factive understanding account is untenable, they should express similar concerns with regard to abstraction.
Moreover, it turns out that it is unclear how exactly should one treat various assumptions employed in the model. I also ague that one prominent strategy for maintaining the facticity condition due to Michael Strevens does not work in this case.
Second, I introduce a new framework which allows for entertaining the facticity condition together with the fact that models often are in various ways distorted representations of phenomena. Furthermore, my analysis shows that authors should be more careful when using the notions of abstraction and idealization.