Medieval thinkers unanimously believed a human soul has various powers. Yet, the latter point is also nearly the only one they agreed upon. In the paper, I focus on two contrary opinions maintained by Henry of Ghent and William of Ockham. Whereas Henry of Ghent held powers of the soul are defined with respect to the activities they are powers-for, Ockham refuted such a contention. To make his point Ockham launches a thought experiment: if God created an intellective soul without creating anything else, wouldn’t the powers in this soul still exist fully? Upon succinctly presenting Henry of Ghent’s view on the powers of the soul, I provide a detailed analysis of Ockham’s counterargument. I argue Henry could still reply to Ockham’s rebuttal, and show how the latter bares a remote resemblance to Avicenna’s flying man argument.