God, as the first cause of all that exists and can be known, fulfills the role of such a universal principle of intelligibility.

Zabarella reconstructed the process of intellection on the lines of sense-perception, that is that the intelligible species, produced concurrently by the phantasma and the illuminating agent intellect, moved the possible intellect into cognition. To be known, the phantasma, which was gained by sense-perception, had to undergo a double process. Itself material and consequently containing the universal structure needed in science only in a confused and unintelligible way, it had to be illuminated