Part 1
No shadow can see itself... nor does it want to; the lower (in-the-dark) parts of us that don't want to be illuminated will not agree to stand in the light that reveals them. However, there are also higher parts of us that know this truth, and that can -- by a higher will -- hold these unconscious parts of us in the presence of that light... so that the light can do what only it can do: integrate (into itself) that unconscious nature upon which it acts.
Part 2
Spiritually speaking: He exercises one part of himself whenever he feels like doing so, and that's good. But, better yet... is when he doesn't feel like exercising, and works to do so anyway. Why? Because each time he works through what he doesn't want to do, he exercises two parts of himself at the same time: first, there's the one part made stronger for his exertion, as is natural; but, at the same time, he also strengthens his will over the parts of himself that only agree to act when they feel like it. And so it goes: by working within himself -- by doing what he doesn't want to do -- he wins an inestimable new strength that can be gained in no other way.