A -> B -> A -> B -> C

You: "Says who that it's even possible to focus all your willpower on one thing?"

Him: "If you recognize the deepest essense of all your wills, you focus all your willpower on that".

You: "Says who that such an essense exists?"

Him: "Do you know what is a will and what is essense?"

You: "Essense is the reason of something else, and a will is prefering reality in one form over another. You can see that the definition of will is the essense, but that means nothing".

Him: "D****t.."

You won!