Comprehending the incomprehensible and expressing the inexpressible was a life-task for Nicolas of Cusa, a tireless seeker of truth and hunter of wisdom. The perennial philosophical questions of knowing and expressing are central in Cusanus’ thought. In Cusanus’ philosophical and theological works one can find a peculiar coincidence between comprehension and incomprehension, effability and ineffability. Cusanus leads a seeker of truth from knowledge to learned ignorance and from speaking into divine silence. In this book, the author investigates Cusanus’ concept of ineffabilis, the possibilities and the limits of human knowledge and language, and the necessity and the impossibility of naming something precisely. Cusanus’ philosophy of ineffabilis is applied to the intercultural philosophy, especially to the field of dialogue between cultures and religions. Practical rules and conclusions are drawn for a successful dialogue between people of different cultures and religions, for the cause of unity and peace.