The other day, reading the New York Post’s Page Six gossip page, I was surprised to find a picture of me, followed by the lines: “ABC’s John Stossel wants the government to stop interfering with your right to get high. … The crowd went silent at his call to legalize hard drugs.”

I had attended a Marijuana Policy Project event celebrating the New York State Assembly’s passage of a medical-marijuana bill. (The bill hasn’t yet passed the Senate.)

I told the audience I thought it pathetic that the mere half passage of a bill to allow sick people to try a possible remedy would merit such a celebration.

Of course medical marijuana should be legal. For adults, everything should be legal. I’m amazed that the health police are so smug in their opposition.

After years of reporting on the drug war, I’m convinced that this “war” does more harm than any drug.

Independent of that harm, adults ought to own our own bodies, so it’s not intellectually honest to argue that “only marijuana” should be legal — and only for certain sick people approved by the state. Every drug should be legal.

“How could you say such a ridiculous thing?” asked my assistant. “Heroin and cocaine have a permanent effect. If you do crack just once, you are automatically hooked.

Legal hard drugs would create many more addicts. And that leads to more violence, homelessness, out-of-wedlock births, etc.”

Her diatribe is a good summary of the drug warriors’ arguments. Most Americans probably agree with what she said.

But what most Americans believe is wrong.

Myth no. 1: Heroin and cocaine have a permanent effect.

Truth: There is no evidence of that.

In the 1980s, the press reported that “crack babies” were “permanently damaged.” Rolling Stone, citing one study of just 23 babies, claimed that crack babies “were oblivious to affection, automatons.”

It simply wasn’t true. There is no proof that crack babies do worse than anyone else in later life.

Myth no. 2: If you do crack once, you are hooked.

Truth: Look at the numbers — 15% of young adults have tried crack, but only 2% used it in the last month. If crack is so addictive, why do most people who’ve tried it no longer use it?

People once said heroin was nearly impossible to quit, but during the Vietnam War, thousands of soldiers became addicted, and when they returned home, 85% quit within one year.

People have free will. Most who use drugs eventually wise up and stop.

And most people who habitually use drugs live perfectly responsible lives; their habits are invisible to their neighbors. As Jacob Sullum writes in “Saying Yes,” there is a “silent majority of users: the decent, respectable people who, despite their politically incorrect choice of intoxicants, earn a living and meet their responsibilities.”

In 2005, the British Journal of Health Psychology reported that a study of 126 long-term heroin users showed that: “Participants had levels of occupational status and educational achievement comparable to that in the general U.K. population, and considerably higher than typically found in heroin research.”

The researchers advised, “Drug research should more fully incorporate previously hidden populations to more fully inform theory and practice,” adding that the “pharmacological properties of specific substances should not be assumed to inevitably lead to addictive and destructive patterns of drug use.”

Myth no. 3: Drugs cause crime.

Truth: The drug war causes the crime.

Few drug users hurt or rob people because they are high. Most of the crime occurs because the drugs are illegal and available only through a black market. Drug sellers arm themselves and form gangs because they cannot ask the police to protect their persons and property.

In turn, some buyers steal to pay the high black-market prices. The government says heroin, cocaine, and nicotine are similarly addictive, and about half the people who both smoke cigarettes and use cocaine say smoking is at least as strong an urge. But no one robs convenience stores for Marlboros.

Alcohol prohibition created Al Capone and the Mafia. Drug prohibition is worse. It’s corrupting whole countries and financing terrorism.

The Post wrote, “Stossel admitted his own 22-year-old daughter doesn’t think [legalization] is a good idea.”

But that’s not what she said. My daughter argued that legal cocaine would probably lead to more cocaine use. And therefore probably abuse.

I’m not so sure.

Banning drugs certainly hasn’t kept young people from getting them. We can’t even keep these drugs out of prisons. How do we expect to keep them out of America?

But let’s assume my daughter is right that legalization would lead to an increase in experimentation, and that would lead to more addiction. I still say: Legal is better.

While drugs harm many, the drug war’s black market harms more.

And most importantly, in a free country, adults should have the right to harm themselves.

Mr. Stossel is co-anchor of ABC News’ “20/20” and the author of “Myth, Lies, and Downright Stupidity.” © Creators Syndicate, Inc.