The ideas of rebirth from death, or purification through pain are as old as human life itself. And, certainly, this recession has been pretty merciless about sorting the wheat from the chaff. Poor businesses have gone under, over-leveraged ones have had to get economically realistic pretty fast, and even fairly solid businesses have had to reassess what they thought they were about. Those that are left now the dust has settled can probably congratulate themselves on being leaner, meaner and generally healthier than they realised.