In November 1994, Dallas Willard spent a day at Biola University for what was called a Colloquium. He gave two lectures the second of which deals with a topic which is extremely important for Dallas: the soul.
The concept of the soul is something that develops in Dallas's mind over his life. In this lecture he is dealing with soul, not in the sense that he does in his Renovation of the Heart, but in the sense of the non-physical part of humanity. Deep into the lecture he gets to talking about what "the stuff" of the soul is. And after giving a list, he says "That's the stuff!" For those confused about what Dallas means by soul as substance, this is a lecture to be familiar with.