18. Be it known that charity and faith make a one as do the will and the understanding, for charity is of the will, and faith is of the understanding. And in the same way, that charity and faith make a one as do affection and thought, because affection is of the will, and thought is of the understanding. And also that charity and faith make a one as do good and truth, because good is of affection which belongs to the will, and truth is of thought which belongs to the understanding. In a word, charity and faith make a one as do essence and form, because charity is the essence of faith, and faith is the form of charity. This shows that faith without charity is like a form without an essence, which is not anything at all; and that charity without faith is like an essence without a form, which likewise is not anything at all.