Mary Douglas, Purity and Danger: An Analysis of Concepts of Pollution and Taboo (1966; London Routledge, 2002): ‘There is nothing fearful or unreasoning in our dirt-avoidance: it is a creative movement, an attempt to relate form to function, to make unity of experience.’  I’m struck by the way Douglas takes the attempt to make unity of experience not just as creative but as positively so. Something the reverse is surely true? Lady Macbeth makes a huge unity out of her dirt-avoidance, after all.
Douglas goes on: ‘rituals of purity and impurity create unity in experience. So far from being aberrations from the central project of religion, they are positive contributions to atonement. By their means, symbolic patterns are worked out and positively displayed. Within these patterns disparate elements are related and disparate experience is given meaning.’
It’s not just that this meaning is as likely to be ‘stone adulterers’, ‘kill gays’ and ‘foreigners are vermin’. It’s that these sorts of meanings are actually the horizon for this mode of conceptualising purity, surely. I know; I’m being crass. But ‘generating meaning’, though I'll admit it is 'positive', is by the same token neither ethically or ideologically neutral.