They want to rearrange their consciousness. They want to experience the changes they've observed coming over adults who do their own rearranging to varying degrees of frequency.

In pursuit of this adventure, the couple, Jack and Emma, use different drugs of choice.

Jack brings with him a flagon of cider. Emma carries a little bag of cannabis, and the incidentals required to roll a joint.

On that day when they get out of their heads for the first time, Jack and Emma enter a new world. They become little cogs in serious industries.

They are now consumers, set up to be targeted by big business.

Emma, if she wants to indulge her drug of choice from time to time, will have to fraternise with criminals. Her contact will be a dealer, who may in the course of his work be a violent person, because violence is the law in the drugs market. Her dealer may also be dealing in other markets, such as heroin, a drug that, both socially and healthwise, is in a different league to cannabis.

She'd better get used to feeling unclean if she wants to continue to smoke her pot.

Maybe, in a reflective moment when she is indulging, she might muse that at least she doesn't have to deal with property developers, bankers or estate agents to get her kicks.

Emma will also have to endure society's attitudes towards her habit. According to all sorts of commentators, from senior politicians down, Emma is responsible for young men getting their heads blown off in the more disadvantaged areas of Dublin. There is, she is told, a direct correlation between her . . . what she thought of as harmless and unobtrusive . . . habit and the extreme but targeted violence that is now prevalent.

If Emma was in a small minority, she would find all of this disturbing, but her habit is fairly typical of her age group.

According to an Oireachtas report published last week, 300,000 young people, those between the ages of 16 and 25 use cannabis today. The 2002 census recorded that there are around 640,000 people in that age bracket. If the politicians have their facts straight, nearly half of the state's young people are in Emma's position, criminalised, degraded by authority and held responsible for death and bereavement.

Jack, by contrast, is on the pig's back, a model citizen. As a budding boozehound, he will be joining a culture where his drug of choice is celebrated wildly.

Everywhere he turns, the great and the good are in communion with him.

The purveyors of Jack's drug of choice are highly regarded . . . or at least greatly feared . . . by politicians of all hue, but particularly those of the state's largest party. The country's leader, Bertie Bass, revels in his role as a pint man. A few years back, the deputy leader used a helicopter at state expense to open another outlet for the sauce.

The industry itself wields huge clout. Sports sponsorship has been practically colonised by the drug.

Everywhere Jack looks, his drug of choice is being foisted on him, and those of his age group because they are the most valued customers. Sometimes poor Emma can't get next or near her drug of choice, but Jack can't get away from his, wherever he looks.

When some spoilsports wanted to tighten up the drink advertising market to protect children, the government wouldn't have it and let the industry draw up its own voluntary code.

Then there's the fatal violence, the extent of which dwarfs that associated with illegal drugs. The National Safety Council estimates that 40% of road deaths . . . around 160 lives a year . . . are attributable to drunk driving. Is anybody to blame for promoting and protecting a culture where this is inevitable? Is anybody responsible for the failure, for instance, to delay the introduction of mandatory breath testing for seven years, costing, perhaps dozens if not hundreds of lives?

Two drugs, one demonised, the other celebrated and milked for all its worth. Is there really anything else to separate them?