A cross-party group of MPs this week agreed that homeopathy should not be funded by the NHS: nobody has yet agreed, ­however, the extent to which the health service is funding homeopathy. The Society of Homeopaths estimates £4m a year; health minister Mike O'Brien put the spend at £152,000 a year. Is that the whole problem here? Can homeopaths just not count? If it really is £4m, this is a problem 10 times smaller than the indigestion blunder, in which ­Gaviscon's makers allegedly sharp-dealt their way into a huge contract that could have been undercut by almost anybody (I mean "10 times" literally, not as a figure of speech). If it's worth £152k, we can file that under "even smaller peanuts".

There has never been a hotter, yet less substantial potato than the argument about homeopathy. The controversy it generates is fractionally more comprehensible when it concerns endorsement or not by the chief custodians of the nation's health, but the passion far predates this: when it was just a way for cranks to waste money, homeopathy aroused baffling hostility. I would never dispute that conventional medics were right, they have an evidence base, they have a peer-review system, they have all this scientific armoury that we believe – maybe rightly – saves us from the tedium of having to argue, but I can never shake the question … what do you care, pointy-heads, what hippies are spending their money on?

Even when the NHS is involved, these issues are still not as large as they're made out to be. Dr Sara Eames, president of the Faculty of Homeopathy and also a GP, remarks: "Placebo is an effect of every treatment, it's not the province of homeopathy." The epidemiologist Kerr White wrote once to the Lancet: "A 1963 paper in Medical Care reported a two-week survey by 19 GPs in a northern industrial town. They recorded the 'intent' of each prescription written. In only 9.3% of the prescriptions for proprietary drugs was the intent specific for the condition for which it was prescribed. Another 22.8% were of 'probable' benefit; 27.2% were of 'possible benefit'; 28.2% were 'hopeful', and 8.9% were regarded as a 'placebo'; 3.6% 'not stated'." Yes, the 1960s are too long ago to be statistically useful. But never mind statistics, how about a sportsman's bet? I bet you those percentages are still true.

It is reasonable to regulate the claims a homeopathic medicine can make on its packaging, but don't have kittens. Homeopaths are just as bad in the ­having of unnecessary kittens. What do they care if the medical establishment refuses to believe their unprovable claims? Can't they just lead us into the light by example, by living incredibly healthy, happy lives?

Personally I'm a hypochondriac, so both conventional and homeopathic medics shun me in unison. The only people who take me seriously are quacks. From a position of such impartiality, may I observe that this argument has almost nothing to do with medicine? Perhaps the homeopaths are one part medicine, diluted by a million parts of anti-authoritarianism: possibly the doctors would claim to be motivated by pure science, but the energy of their attack makes me smell a rat.

Even if homeopathy has no evidence base at all (and homeopaths dispute this – see how rigorously I maintain my ­neutrality), much of conventional ­medicine has none either (a rather mordant BMA statistic puts the figure for conventional medicine with an evidence base at 40%: a qualitative study in Oxford puts it at 82% – but that still leaves nearly 20% of treatments unmoored from demonstrable efficacy, which amounts to a lot more money than has ever been spent on homeopathy). Yes, an evidence base is a rationalist's ideal, but things are more complicated than that. There's very good evidence to show that telling people to eat healthily and exercise more actually makes them put on weight, but when did that ever stop a GP?

I believe this is what sociologists call an "identity builder" – a shorthand for announcing what sort of person you are. Against homeopathy are those who think of themselves as rationalists – intelligent people who hold a reliable course against the buffeting of fads and fashions, prejudices, fripperies, superstitions and the gamut of human idiocy. If they really were rational, they would be able to admit there are many corners of conventional medicine that are mainly guess and empathy, but they cannot countenance a world in which a debate might have two answers. Their very passion for reason undermines their position.

In favour of homeopathy are those who see themselves as anti-authoritarian, maybe a bit subversive, independent thinkers, imaginative, empathetic. They won't be silenced, either, because crucial to this whole identity is that you won't let the suits tell you how to think.

What's interesting is that we've chosen this, of all issues, to line up behind. In the US, they have herrings just as red – abortion isn't really about ­foetuses, the gun debate isn't really, or not wholly, about guns, and Darwin must be chuckling from his grave at the heat he suddenly generates. But when Americans are looking for trigger issues, they choose large matters of life, death and the beginning of all things. We choose homeopathy! The very humility of this makes me, fleetingly, proud to be British.