“…the Kashrut survived approximately three millennia not because of its “rationality” but because the populations that followed it survived.
Rationality is not what has conscious verbalistic explanatory factors; it is only what aids survival, avoids ruin.”
Do you draw a distinction between the survival of a community with a distinct faith and the survival of the individual people who hold that faith?
Are you saying that an individual who pursues a strategy of assimilation (eg Lebanese diaspora), or conquest without imposing belief (eg Mongols) are less rational, even if it means that their genes are more widely dispersed and their progeny arguably more adaptable and prevalent?
Surely beliefs that successfully perpetuate the survival of the community and its idiosyncratic ways may not be ‘rational’ for the survival and welfare of many/most of the individuals who hold them, even if a few do survive?
If you were to replace the word ‘rational’ with ‘useful’ throughout this essay, would it not be clearer?