The modes of being are defined in terms of different characteristic combinations of ‘existential moments’. The existential moments mostly concern either an object's temporal determinations (or lack thereof), or the different dependencies it bears (or does not bear) to other sorts of object. Indeed in drawing out his existential moments, Ingarden goes beyond Husserl's influential work on dependence to distinguish four different existential moments of dependence (and their contrasting moments of independence):
In so doing, Ingarden develops one of the richest and most detailed analyses of dependence ever offered, providing distinctions in the notion of dependence that can clarify many philosophical problems including but certainly not limited to the realism/idealism problem.
Ingarden's four highest existential-ontological categories or ‘modes of being’ are: Absolute, Real, Ideal, and Purely Intentional.
Thus the realism/idealism controversy can be reconfigured as the controversy over whether the so-called ‘real world’ has the real or purely intentional mode of being.