This essay focuses on the specific notion of imaginatio that Nicholas Cusanus defines in his theoretical reflection. I shall analyze its applications (or functions) both in relation to the discursive kind of human knowledge and, more in general, in connection with the thought. The cusanian theory of mind reveals a triple use of this faculty, which allows reason [ratio] to produce not only forms concerning the sensible world, but also forms of pure rationality – completely free of perceptual impressions – such as those regarding the lexicon of mathematics, geometry and of planning thought. In this sense, the rational and imaginative dynamics develop the whole perspective of the human mind. In addition, Cusanus recognizes another innovative role of the imagination, which has to do with the capacity to reflect on God in symbolic terms. It provides the intellect with a special interpretation of the rational figures and forms, in order to convey the only possible way of argument around the First Principle of everything.