When you say that the claim, that happiness in society rests on delusions, isn't serious and that it's worthy of being bandied about only in a pub, you're expressing the science culture's contempt for philosophy. This claim is broad enough to be philosophical, to fall outside the scope of psychiatry, because psychiatry maintains its scientific standing by relativizing mental health and disorder to social functions and presuppositions. Psychiatry thus can no longer evaluate entire societies, which leaves the question to philosophers. That is, psychiatrists don't want to presume any system of values since they want to seem objective and empirical. Mental disorder for them is only a cause of someone's failure to perform his or her social obligations.
But that condescension flows also from covert philosophical presuppositions, which means the condescension is the self-refuting scientistic or positivist kind, familiar to philosophers from the early twentieth century, when it collapsed and disgraced itself.
You only have to notice that in every large society, there are many followers and relatively few social outsiders, and the outsiders are often obsessed with subversive philosophy (or perhaps with paranoid and paralyzing fears). Either way, they're alienated from the religious myths and cultural norms that mind the masses together.
This is basic anthropology. From the shamans and the elite priests to the Cynics and mystics, prophets, messiahs, drifters, artists, autists, and so on, those who wallow in harsh truths fall outside the boundaries of acceptable society. Religious myths may have deep metaphorical meaning. But after the rise of secular modernity, when the myths were still taken literally or exoterically, they became obvious delusions in the sense of being outlandish relative to the the new science-centered worldview.
Psychiatrists don't want to touch this Freudian point because it's subversive and they'd lose their social standing. For the same reason, new atheists whitewashed the implications of atheism, and tried to sell atheism with happy-talk, ignoring Nietzsche's problem about how disastrous is the death of God.
I agree that tribalism or the need to define our social identity is a factor here. The question I raise is whether there can be a purely nondelusional construction of social identity. Can a group of people be bound together by an insistence only on the cold hard facts? Or do we need to indulge in fictions to fill in the blanks and to comfort ourselves and carry on?
