Your mind can't step back and watch its own emotions like an outside observer. It can't decide when to let them go too far. Instead, your mind becomes the emotion itself. Once that happens, it can't control what used to be healthy strength — now twisted and misused. Passion and reason aren't separate kingdoms in your head. They're just your mind changing for better or worse. So how can reason save itself once anger has beaten it down? How can it untangle itself from this messy mix where the worst parts have taken over?
The mind does not stand apart and view its passions from without, so as not to permit them to advance further than they ought, but it is itself changed into a passion, and is therefore unable to check what once was useful and wholesome strength, now that it has become degenerate and misapplied: for passion and reason, as I said before, have not distinct and separate provinces, but consist of the changes of the mind itself for better or for worse. How then can reason recover itself when it is conquered and held down by vices, when it has given way to anger? or how can it extricate itself from a confused mixture, the greater part of which consists of the lower qualities?