St. Teresa of Avila: soul and spirit

"Certain interior effects give the certitude that there is, in certain respects a very real difference between the soul and the spirit. Although in reality they are but one, we sometimes perceive a division between them that is so delicate it seems the one functions in one way, and the other in another. . . . [De Lubac's ellipses] There are so many things in our innermost depths, and things so subtle, that it would be boldness on my part to undertake to explain them. We will understand all that in the other life, if God ... deigns to admit us to the dwelling where we will have understanding of all these secrets."

qtd. Theology in History, p 158 (from Interior Castle)