15. The progression of these in their series is like the progression of all things belonging to the will through the understanding into acts in the body. The will produces nothing from itself without the understanding, and the understanding nothing from itself without the will: they must act in conjunction in order that anything may exist. Or, what is the same: affection which is of the will, produces nothing from itself except by means of thought, which is of the understanding; and conversely: they must act in conjunction in order that anything may exist. For consider: if from thought you remove the affection which is related to some love or other, can you think? or if from affection you remove thought, can you be affected by anything? or, what is the same, if from thought you remove affection, can you speak? or if from affection you remove thought or understanding, can you do anything? It is the same with charity and faith.