If everything extends from Will, in Schopenhauer's view, then 'denial of the will' is itself a willful act. Which is fine, I mean, matter acts upon matter in the same way. I think a better term of description though is not the act of denial of will, but instead, the refinement and harmonization of Will. It would seem that what Will ought to strive for is a discernment that depends on the level of consciousness that's been achieved. In other words, we are at a level where we ought to strive towards reducing suffering, as we humans define it. We ought to refine our own desires so that they are more harmonious with each other.