Our idea of dirt is compounded of two things, care for hygiene and respect for conventions. The rules of hygiene change, of course, with changes in our state of knowledge. As for the conventional side of dirt-avoidance, these rules can be set aside for the sake of friendship. Hardy's farm labourers commended the shepherd who refused a clean mug for his cider as a ‘nice unparticular man’:

‘“A clane cup for the shepherd,” said the maltster commandingly.

‘“No — not at all,” said Gabriel, in a reproving tone of considerateness. “I never fuss about dirt in its pure state and when I know what sort it is … I wouldn't think of giving such trouble to neighbours in washing up when there's so much work to be done in the world already.”’