Professor Roger Pertwee, is the professor of Neuropharmacology at Aberdeen University so there's not much about the effects of the drug on the human body that he doesn't know.
While he acknowledges that there are issues with Cannabis, he argues that the current approach of decriminalisation does more harm than good and has suggested a way forward. Today's Independent quotes him as saying:
"You'd need to have a minimum age of 21, and I would suggest you might even have to have a licence," said Prof Pertwee, from the University of Aberdeen, who pioneered early research on the effects of cannabis in the 1960s and 1970s.
"You have a car licence and a dog licence; why not a cannabis licence?"
The idea would mean only those not suffering from a serious mental illness or at risk of psychosis would be legally allowed to buy the drug.
He was clear that:
"We're allowed to drink alcohol and smoke cigarettes. Cannabis, if it's handled properly, I think is no more dangerous than that."
I think there might be some merit in what he's saying. If there was a proper licensing regime, the Police could concentrate their efforts on the people who operated outside that system. I wondered if there would be an illiberal element to restricting eligibility for licences - but we have that principle anyway in the way we deal with shotgun and driving licences.
What is clear is that the current policy isn't working. By insisting that all drugs should remain illegal, the potential for someone using a less harmful drug to be lured by an unscrupulous dealer into a much more dependent relationship on substances which will rule and ruin their lives is clear.
I think we really need to have a proper, open debate about drugs and the best way to minimise the harm that they cause. We should make policy on the basis of evidence and not on the basis of prejudice or fear. It's quite strange that it's perfectly legitimate, even acceptable to say you have a hangover, or you got absolutely hammered on booze at the weekend. However, if someone came into work and said they'd been stoned on Saturday night, they'd likely be sacked on the spot, even though both activities for most people have the same amount of risk.
It's time to cast aside the blinkers and take a cold, hard look at the evidence.