But I haven't at any time been hindered in my will, nor forced against it. And how is this possible? I have bound up my choice to act against the will of the Gods. The Gods will that I be sick, such is my will. They will that I should choose something, so I do. The Gods will I should choose something, or something be given to me - I wish for the same. What the Gods do not will, I do not wish for.
From the meditation notes, this appears to be all about preparation and acceptance. The writer shares a story regarding Eisenhower before the invasion at Normandy. In his letter to his wife, he stated his forces had done all they could to be ready. They drilled, did dry runs, and had information on the enemy.
All that was left was the doing, and he couldn't determine the outcome. So, no matter how much preparation, the outcome is not always what we wish for. But we have to accept it.
Now the writer identified the Greek Gods as determining the outcome. Just as many today will identify God as the entity that determines the outcome. The thrust of the quote works for me, but the God or Gods part does not.