One cannot fix a broken leg by reflection, and in a similar way depression is a physical disease and one cannot fix it with a simple reasoning. At the same time, depression is the result of a stratification of wrong habits of behavior and thinking. For this reason, depression can be faced with reason, but not with that reason that shows the black judgments of the depressed person to be void, yet with the reason that tells us which habits we can change in order to remove the systematic conditions which provoked depression. And when I write habits, it is better to repeat it, I mean both physical behaviors and concepts used to read the world.
Following this, depression appears to be characterized by a double nature. On one side it is a concrete issue, much more solid than single reasonings made up by worlds, on the other side one can attack depression by assuming a suitable vision of the world and keeping it for a long time, so that this vision can stratify its effects in all the regions of our experience.