I loved Latin at school. My award for Latin poetry recital is carefully preserved and I remain mildly hopeful that, one day, it might even prove useful. Poetry aside, it was then seen as necessary to become a lawyer. For the first few years of practice those Latin sayings encapsulating legal rules became firmly lodged in my head. Then they were no longer compulsory, plain clear English becoming the rule. Quite right. But one saying seems particularly apt these days: Ex turpi causa non oritur actio – no-one can make a claim based on their own dishonourable conduct. More widely, it expresses the idea – or, perhaps, the hope – that people, governments even, should not be able to take advantage of the damage caused by their failings to do that which they would not otherwise get away with.