Cambridge's UIT Press has established a well-deserved reputation for publishing clear, engaging, evidence-based books on controversial subjects. Titles like Sustainable Energy Without the Hot Air and Sustainable Materials – with Both Eyes Open remain two of the best books I've read on the relationship between environmental responsibility, climate, material wealth, science and engineering — books that profoundly changed the way I understood these subjects.

The latest in this series is Drugs: Without the Hot Air (UK), by David Nutt. If Nutt's name rings a bell, it's because he was fired from his job as UK drugs czar because he refused to support the government's science-free position on the dangers of marijuana, and because he wouldn't repudiate a paper he wrote that compared the harms of taking Ecstasy to the harms of horseback riding (or "equasy").

Like the other writers in the series, Nutt is both committed to rigorous, evidence-based policy and to clear, no-nonsense prose that makes complex subjects comprehensible. He begins and ends the book with a look at the irrationality of our present drug policy, recounting a call he had with then-Home Secretary Jacqui Smith, who was furious that he'd compared horseback riding harms to the harms from taking MDMA. Smith says that "you can't compare harms from a legal activity with an illegal activity." When Nutt asks why not, she says, "because one is illegal." When he asks why it is illegal, she says, "Because it is harmful." So he asks, "Don't we need to compare harms to determine if it should be illegal?" And Smith reiterates, "you can't compare harms from a legal activity with an illegal activity." Lather, rinse, repeat, and you'll get our current drugs-policy disaster.

Nutt has been talking about harm reduction and evidence-based policy for drugs policy for years, and he often frames the question by pointing out that alcohol is a terrible killer of addicts and the people around them, and a disaster for society. But if he was to synthesize a drug that produced an identical high to alcohol, without producing any of the harms, it would almost certainly be banned and those involved in producing, selling and taking it would be criminalised. We ban drugs because they are harmful and we know they are harmful because they are banned. Drugs that we don't ban — tobacco, alcohol — are "harmful" too, but not in the same way as the drugs that are banned, and we can tell that they are different because they haven't been banned.

Nutt has choice words for the alcohol and tobacco industries, who often frame their activity as being supported by responsible choice, and claim that they only want to promote that sort of responsibility. But as Nutt points out, if Britain's drinkers hewed to the recommended drinking levels, total industry revenue would fall by 40% — and the industry has shown no willingness to regulate super-cheap, high-alcohol booze, nor alcopops aimed at (and advertised to) children and teenagers.

Nutt compares the alcohol industry's self-regulated responsible drinking campaigns to a campaign that exposed students in East Sussex to factual information about the industry's corruption of public health messages, its ferocious lobbying efforts, and the cost of drinking to wider society. It turns out that exposing alcohol industry sleaze is vastly more effective at discouraging student drinking than anything sponsored by the industry itself.

From his discussion of legal drugs, Nutt moves on to factual accounts of the impact of illegal/controlled drugs, from "legal highs" like "meow meow" to opioids to cocaine to prescription painkillers and steroids to psychedelics. Each chapter is a bracing, brisk, no-nonsense inventory of what harms and benefits arise from each substance, the history of their regulation, and the ways in which changes to the means of taking the drugs changes the outcome. Laid out like this, it's easy to see that prohibition isn't ever the right answer — not for science, not for society, not for justice, and not for health.

There's also a sense of the awful, tragic loss to society arising from the criminalization of promising drugs. A chapter called "Should Scientists Take LSD?" surveys the literature preceding the evidence-free banning of LSD, and the astounding therapeutic benefits hinted at in the literature.

The book closes with the War on Drugs, and the worlds' governments own frank assessments of the unmitigated disaster created by Richard Nixon's idiotic decision 40 years ago. Nutt analyzes the fact that policymakers know that the War on Drugs is worse than the drugs themselves (by a long shot), but are politically incapable of doing anything about it, not least because politicians on all sides stand poised to condemn their opponents for being "soft on drugs."

After this, there is a frank chapter on talking with your children about drugs. Nutt is a parent and has some regrets about how he approached the subject with his own children (one of his sons was stalked by a British tabloid journalist, who tricked him into friending him on Facebook, which gave the journalist the opportunity to gank photos of the young man smoking marijuana). As a parent, this stuff really resonated with me — sensible advice that focuses on establishing and maintaining trust.

Drugs: Without the Hot Air