There is a difference between an illusion and a delusion. I think that there is some confusion about that here.
An illusion contains the idea of falsehood or delberate misleading by one person to another, whereas delusion is a false belief or idea held individually, perhaps shared with no one. Thus whilst we may have our own delusions, recognised or unrecognised, we are also unable to see the illusions presented to us by others. It is the latter illusions that underpin much zealotry and and unhappiness in our society. it is we who allow the unscrupulous amongst our leaders to use such illusions to extend their personal power, at the expense of public good.
We need our dreams, our aspirations and our beliefs, but we have to guard against having them used by others for their own illusory ends.
