In case anyone's interested, here is where my confusion stemmed. This is a cut and paste from Purnell's recommended site:
The in-itself is solid, self-identical, passive and inert. It simply "is." The for-itself is fluid, nonself-identical, and dynamic. It is the internal negation or "nihilation" of the in-itself, on which it depends. Viewed more concretely, this duality is cast as "facticity" and "transcendence."

Is it just me? Or is this stuff a bit difficult to understand?