It's the greatest of political sins, to fail to make use of a good crisis. One example of those trying to do so might be the recent EU report on financial market regulations. Hedge funds and private equity are to be brought under tighter control despite their having nothing whatsoever to do with the current problems.

Another attempt which is unfolding under our very eyes is the attempt to portray this swine flu as being an example of the evils of industrial farming.

The Mexican swine flu, a genetic chimera probably conceived in the faecal mire of an industrial pigsty, suddenly threatens to give the whole world a fever.

It's not a chimera, of course, as that would be mixed DNA rather than mutated. It's also an interesting thought for that's not really how we expect zoonoses to arise. For a disease to spread from one species to another, to become cross infectious, we actually think we need to have the two species living in close proximity. Like the Hong Kong bird flu of 68 came from the way in which small holding farmers in that at the time poor country lived cheek by jowl with their birds. Or SARS from Vietnam from the similarly close proximity of stock and human. (No, Spanish flu was not thought to come from humans associating too closely with Spaniards.) That is, we expect such diseases, and we've seen that they do historically, to come not from industrial farming, but from small scale peasant farming. Sleeping above the stock (rather than, erm, with it) is the cause, not having tens of thousands of stock that have little inter species contact.

But of course this should not get in the way of using a good crisis to get whatever it is that you've already decided you want, as Caroline Lucas shows us

More research is urgently needed to explore the potential link between industrialised animal farming, and the spread of disease. Some elements of the Mexican media are already pointing to the potential role of intensive pig farming in Mexico, which has grown substantially in recent years, with some giant operations raising tens of thousands of pigs at a time.

Very well, let us have some more research. How about a bit of empiricism, some collection of relevant facts?

But agricultural in­spec­tion officials say there is no swine flu virus among the pigs at these farms.

So theory says we wouldn't expect large single species farms to produce zoonoses and the facts say that it didn't. Another glorious theory ruined by those pesky facts perhaps? But unfortunately I doubt that will be enough to drown out the siren voices desirous of making good use of this crisis.