The chronic

There's a wonderful scene in Generation Kill, the HBO mini-series following a battalion of US Marines through the confusion of the 2003 invasion of Iraq, when the embedded journalist asks Lt Col Stephen 'Godfather' Ferrando why he speaks with such gravelly whisper.

"Throat cancer," Godfather rasps laconically.

"You a smoker?" asks the journalist.

"No," a long pause, "just lucky, I guess."

I've been thinking of this exchange as conversations with friends and acquaintances have touched on the various illnesses - heart disease, liver problems, cancers, degenerative conditions - that are beginning to intrude on forty-something lives. Almost invariably, the first reaction is, "But s/he doesn't smoke/drink that much/eat turkey twizzlers/[insert bad habit of choice]."

I wonder whether this surprise at people becoming ill despite their virtuous lifestyles is a peculiarly modern way of thinking. Medical science has made huge advances in digging beneath the symptoms to identify the underlying epidemiology, physiology and causes of diseases, and equally great strides in identifying the environmental or behavioural factors that can increase or decrease susceptibility to particular diseases.

But only very rarely has science identified a straightforward and un-varying causation: if you do x, you will contract y; if not, not. 'Luck' (which is actually how we describe causal factors that we don't understand) continues to play a part: only an idiot would deny the links between smoking and lung cancer, but 10 per cent of lung cancer cases still arise in non-smokers. We prefer certainty, and not to acknowledge that "time and chance happeneth to all" (hence, I suspect, the scrabble to blame non-smokers' cancers on 'passive smoking'). And governments collude in the process, understanding that preventing the damage caused by unhealthy lifestyles works better, and probably costs less, than medical intervention to reverse or mitigate it in later life.

But is this assumption that our lifestyles can protect us from illness really a symptom of modernism, or does it represent the atavistic resurgence of something much older - a perception of disease as a punishment for moral iniquity? This view broke cover in the early days of HIV (memorably satirised in Brasseye's distinction between 'good AIDS' and 'bad AIDS'), and persists in the absurd economic debates about whether smokers pay more in excise duty than they cost in medical care, and in the vilification of poor people for their diets. In understanding epidemiology, have we slipped back to attributing blame?