Culture is an evolved thing. Cultures as a whole, as well as individual elements of culture, survive through time if they are successful at getting living organisms to reproduce them. Cultures, like viruses, may get away with harming the organisms they depend on for reproduction, but they will die out if they kill off their hosts too quickly.
Cultures are different from biological viruses in that humans depend on culture for survival; in that, cultures resemble gut bacteria. If you depend on an organism's survival for your own survival and reproduction, you may benefit from providing a survival benefit to the host organism.
Maritime technology is an example of an evolved cultural element that provides a survival benefit. Many groups have developed seagoing technologies, from canoes to frigates to aircraft carriers. Anchoring technology, for instance, exists in many forms, and the forms share many elements, as if products of convergent evolution. Anchoring technologies that didn't broadly work within the cultural and biological limits of humans have been tried countless times throughout human history, but were not reproduced. The technologies and cultural elements we see today, like the organisms we see today, are only the ones that were effective at surviving and reproducing.
A striking example of the process of the evolution of cultural artifacts is provided by Daniel VanArsdale in his analysis of the evolution of paper chain letters. Chain letters reproduce by convincing humans to make copies of them; those with certain features (such as the "It work" postscript) are more successful at this, and those are the ones that are copied and survive.
Finally, agriculture is an example of a broad category of cultural elements that are reproduced because they increase the survival and (especially) reproduction of the host organism; unfortunately, this increase has come at a cost to the well-being of the host organism.
Sacredness is an Element of Culture
Structures of sacred ideas (including, but not limited to, religions) evolve, survive, and reproduce themselves using humans. Humans appear to exhibit neural adaptations for processing sacredness; however, the sacredness structures themselves are not hard-wired, but vary between cultures. It is only our capacity for thinking in terms of the sacred that does not vary.
Sacredness - cognition in terms of bright-line rules instead of utilitarian analysis - can be a powerful solution to complex coordination problems. Sacredness structures often allow the sacred being to be a proxy for the group. Instead of deciding in each case whether to act in one's own or the group's interest, sacredness causes individuals to always follow sacred rules, generally benefiting the group over the individual. Those who can signal a strong connection to the sacred also signal that they are excellent cooperation partners. A group of sacredness-perceiving organisms can overcome any coordination problem addressed by sacredness rules. Sacredness structures, like consciousness itself, function as interfaces between organisms and each other and between organisms and the world.
Sacredness structures vary, but are not arbitrary: to be successful, a sacredness structure must be adapted to human physiology and cognition and must promote survival and reproduction of the host organism. A sacredness structure (such as a religion or government) will survive and reproduce best if it encourages the use of technologies that promote its sacredness, and if it creates a plausibility structure around itself. Technologies that promote the experience of sacredness include cathedral building, drugs such as ayahuasca, the induction of glossolalia and other forms of hypnosis, snake handling, group singing, and group dancing. Elements of plausibility structures include marriage solemnization (once the province of religion, and now increasingly the province of government) and the treatment of the sick (ditto). Stories, including foundational cultural legends, play a role in maintaining the sacredness structure: these narratives, as folklorist Linda Degh puts it, "deny the right of disbelief or doubt," "express majority opinion," and "are safeguarded by moral taboos from negation and, what is more, from deviation" (from "Tape-Recording Miracles for Everyday Living," in American Folklore and the Mass Media, Indiana University Press, 1994). In this manner, sacredness is maintained through communal reinforcement.
An important feature of sacredness structures is that they present themselves to the affected organism as objectively true. Two organisms subscribing to two incommensurate sacredness structures cannot both be right; however, they both subjectively perceive themselves as unquestionably right. Sacred thinking protects this feeling of unquestionable rightness with such cognitive tricks as the backfire effect (strengthening one's worldview in the face of conflicting evidence) and confirmation bias (the failure to meaningfully incorporate information that conflicts with one's worldview).
Sacredness structures are not just about beliefs. Sacredness structures frequently require host organisms to maintain inconsistent beliefs; as long as effective strategies exist to deal with the inconsistency (such as faith, mystery, or taboo), inconsistency is not fatal to a sacredness structure, and may even be a strength.
The Sacredness Monster
Shouldn't some things be sacred? It is at least theoretically possible that it is welfare-maximizing to carve out a space of the universe and impose sacredness rules instead; special cases of deontological ethics may "win" from a consequentialist perspective.
But can that monster be controlled?
Removing a domain from consequentialist analysis may have unintended effects. Sacredness is perverse. Once a sacred domain is established, moral licensing may allow people to impose harm on others in violation of the supposedly sacred taboo if they convince themselves they are basically consonant with the sacred rules; those able to convince themselves that they're not racist people are more likely to act in a racist manner, for instance (race being a major part of the sacredness structure of our society). In many cases, expression of the sacredness itself may promote the harm that the sacredness, in a utilitarian framework, is designed to protect against; for instance, expressing that child sexual abusers are "monsters" or that a parent would "kill anyone who did that" is actually likely to cause a child to avoid reporting sexual abuse. Talking about sacred subjects is conflated with committing atrocities, to the detriment of all. Considering all of these together, the most insidious aspect is that once a domain achieves sacred status, the very discussion of its effects in utilitarian terms is tabooed.
Sacredness structures are powerful things that distort the utilitarian moral landscape and warp space around them. As Jonathan Haidt puts it, a ring of motivated ignorance surrounds the sacred.
Sacredness structures, like chain letters or agriculture, may promote human welfare or not, but they invariably promote themselves. Indeed, individuals as well as cultures may have reasons for maintaining sacredness that are not at all related to promoting human flourishing.
Sacredness is Tacit
What sacredness is for, then - its function - is to regulate, motivate, and coordinate behavior among the host organisms. Awareness of the function of sacredness may spoil the effect, at least on the same level of awareness. So sacredness must remain tacit. There are good reasons to hide what's going on with the tool of human hypocrisy, especially in the modern world where multiple sacredness structures compete.
For how can sacredness structures compete overtly? Competition on consequentialist grounds violates the very sacredness of the structures. Sacredness structures present to the participating organism as objectively true; competing sacredness structures present as "just wrong," limiting the cognition that can be done.
The sacredness of the equality of races and genders is a particularly fascinating example. In past societies, host organisms got feelings of status and belonging from maintaining systems of strict gender role divisions and of racial separation or castes. (And let me be clear: fuck that.) Our present Western liberal society has attempted to replace those past, ugly (to us) sacrednesses with the sacredness of racial and gender equality and (somewhat incoherently) rape as a special violation of female sacredness. These function almost as meta-sacredness: making sacred a particular kind of "non-compete clause," imposing a taboo on particular methods of competition between groups and sacredness structures. Again, this might well be welfare-maximizing - but there's no way to analyze that without violating the inherent taboos. Frequently, as in the examples above, the taboos themselves seem to promote the harms they seek to vilify.
Sacredness structures, then, are solutions to coordination problems rather than objective truths. They present themselves, however, as objectively true - as values in and of themselves, rather than as tools to promote human values.
Deontological ethics and other forms of sacredness ask us to clap our hands to save Tinkerbell. If we can only believe in the untrue, we can make it true-ish! But at the same time, we are asked to close our eyes to what is really true.
It may be better for the individual to believe in sacredness structures. It may be better to live in ignorance. It may be better for a cow to walk willingly to slaughter, believing she is to be fed.
But we don't call that consent.
See also: Tinkerbell Ethics Part I