POLITICIANS DO NOT care for drugs. It is a topic like religion: since the established position is nonsense, established people do not like discussing it if they can avoid doing so.

Alas, drugs are being pushed on to the establishment from within. First it was Kate Moss, then David Cameron, and then the Advisory Council on the Misuse of Drugs with its report on the criminal classification of cannabis. That is the entire establishment covered: Hoi Poloicracy, Aristocracy and Bureaucracy. There is no hiding. It is time again for “the drugs debate”.

The drugs debate goes like this. Most participants think it right that the production, sale and consumption of recreational drugs, such as cannabis, ecstasy, cocaine and heroin, should be illegal. They point to the damage drugs do to their users’ health: death, brain damage, lung cancer and so on. (All the other harm caused by the drugs trade is a consequence of its illegality and so not helpful to the case.)

Those who think drugs should be legalised — “only the soft ones, of course, we’re not crazy” — come over all John Stuart Mill. Consenting adults in a free country should be able to do to themselves whatever harm they choose. The State may rightly limit our freedom to prevent us from harming others, but not to prevent us from harming ourselves.

Mill was probably right. But the argument is not entirely helpful because it tacitly accepts that people harm themselves by taking drugs. And we live in an age where welfare trumps liberty every time. Modern politicians like to say that it is their very difficult job to find the balance between welfare and liberty. But it is not the least bit difficult to predict on which side their scales will always fall. So, to win our liberty, we must get legislators to see that drugs are in fact good for their users.

This claim will surprise many readers. Has Whyte got his hands on some radical new research about the physiological and psychological effects of drugs? No. I've got my hands on a perfectly orthodox theory of welfare that is always forgotten in “the drugs debate”. Something is good for you if its benefits exceed its costs. Otherwise it is bad for you.

This simple principle means that you cannot properly recommend something by considering only its benefits, nor condemn it by considering only its costs. This latter mistake is the one favoured in the drugs debate. People go on endlessly — and often exaggeratedly — about the health risks of taking drugs, as if this were sufficient to show that drugs are bad for you. This is absurd. If you consider only the costs, then everything is bad for you. Eating has its costs, such as the price of food and the risk of choking. Should we conclude that eating is bad for you?

The real question is not whether drug use has costs. Every activity has. The question is whether these costs exceed the benefits of drug use. It is easy to show that they do not, but we should first recognise what the main benefit is. This should be obvious but, for some reason, nobody involved in “the drugs debate” ever mentions it. The main benefit of taking drugs is that it is pleasurable. In fact, it can be incredibly pleasurable. That is why people do it.

And also why it is good for them. Drug users are simply people for whom the pleasure outweighs the risk of death, illness, addiction and all the rest. In other words, they are people for whom the benefits of drug use exceed the costs. They wouldn’t be drug users otherwise. The same is not true of everyone. Some value health more and pleasure less. For them, drug taking would deliver a net loss. Fine: these people would not take drugs even if they were legal.

The point is not peculiar to drugs. Change the example. Is playing lawn bowls good for you? That depends on the how much you value the upside (the exercise, the company, the nice white outfits) and how much you (dis)value the downside (the exercise, the company, the nice white outfits). If your values make lawn bowls a net benefit, you will play. If not, you won’t. Welfare and liberty are in perfect harmony. People voluntarily do only what is good for them.

Provided, of course, that they are properly informed. If you underestimate the cost of some activity, you might do it even though its costs exceed its benefits. This possibility is sometimes used to justify the criminalisation of drugs. But underestimation cuts both ways. People might fail to do something that is good for them because they underestimate the benefits. Those who have never taken Ecstasy might not know how wonderful it feels. Should it be made compulsory to eliminate this risk?

In 1990, 15 men who had voluntarily cut each others genitals for the sake of sexual gratification were convicted of assault. Why did their consent not stop this from being assault? If it did not, then why is rugby not assault? In the failed 1992 appeal, Lord Lane explained. Consent is a defence only if the physical damage is sustained for a worthwhile purpose. Rugby is a worthwhile purpose; sexual pleasure is not.

I suspect that something similar makes legislators systematically discount the benefits of drugs. It is not enough that people value something. To count it as a benefit, our betters in Westminster must deem it worthwhile. And, as with kinky sexual gratification, they do not consider getting high to be worthwhile.

It is not concern for our welfare that explains the illegality of drug use. It is bigotry.

The author is a philosopher

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