I am in France at the moment and hence this French expression used in English speaking psychiatry crossed my mind: the expression is idée fixe (pron. eeday fix). This describes the condition in an individual who holds an obsessive attachment to a point of view which is unresponsive to reason and argument.
There must be some comfort in arriving at this psychotic position. Once adopted everything is sorted.................
For example being implacably convinced that the Bible is the true source of divine instruction and that seven men in JW headquarters MUST be the link between God and us and that Armageddon is coming any moment now and will kill off unbelievers and leave the world to us who are the only true believers. I have every reason to want to believe this, without this hope my life is worthless.......
Is the JW organisation filled with members suffering (or enjoying) a collective idée fixe?
Perhaps a psychologist here might be able to expand?