  Ingarden’s four highest existential-ontological categories or ‘modes of being’ are: Absolute, Real, Ideal, and Purely Intentional. The absolute mode of being could be exhibited only by a being such as God, which could exist even if nothing else whatsoever ever existed. The ideal mode of being is a timeless mode of existence suitable for platonistically conceived numbers; the real mode of being is that of contingent spatio-temporal entities such as the realist assumes ordinary rocks and trees to be; while the purely intentional mode of being is that occupied by fictional characters and other entities which owe their existence and nature to acts of consciousness. 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. (For further discussion of the Purely Intentional mode of being and its role in the theory of perception, see Chrudzimski 2015 and Uemura 2019)