Few drugs have had as colorful a history, have been the theme of so many cult-classic films or have ignited so many vocal disagreements as marijuana. We are still arguing what to do with it 80 years after Congress passed the Marijuana Tax Act of 1937, which effectively prohibited the non-research use of the drug, and 40-plus years after enactment of the Controlled Substances Act of 1970, which outlawed marijuana.

Today, the debate resembles the “Tastes great! Less filling!” commercials that professional football fans will remember. One side argues that the federal government should continue to treat cannabis as contraband, forbidden to be used anywhere and everywhere. The other side says the states should be free to decide whether and when marijuana can be used, especially for therapeutic purposes.

Perhaps they’re both wrong.

One year after the Marijuana Tax Act became law, Congress enacted the Federal Food, Drug and Cosmetics Act. This law prohibits the interstate commerce of adulterated foods and unsafe drugs. The act also directs the commissioner of food and drugs to examine both types of products, along with whatever is added to them, to make sure they are safe for use and therefore can be distributed interstate. In 1962, Congress barred the distribution of new drugs unless the FDA commissioner first finds them to be safe and “effective.” Since then, Congress has consistently reiterated that the FDA is responsible for making those decisions. The FDA — not the U.S. attorney general, not the states, and not the public.

Why? Because legislators, lawyers and lay people are not qualified to make medical or scientific judgments. (Raise your hand if you took organic chemistry and biochemistry in college. Hmmm, not many hands went up.) The average person lacks the education, training and experience to decide whether a drug is safe and effective or that a substance renders food adulterated. We do not use plebiscites or polls to answer those questions.

Eighty years ago, Congress concluded that the FDA commissioner should make those calls, and America has accepted that judgment ever since. We do not let the public decide which antibiotic, antiviral, antifungal or chemotherapy drugs can be marketed; the commissioner does. We should let him make the same decision here.

Troubled that giving the commissioner that responsibility might be too abrupt a change in federal law to be done at once? Fine. Congress can direct him to chair a task force — with members to be appointed by the president, but to include representatives from the National Institute on Drug Abuse, the National Institutes of Health, the Drug Enforcement Administration, state and local health and law enforcement agencies, and so forth — to prepare a report by Dec. 31, 2019, identifying and discussing all of the regulatory options that the task force deems reasonable, and recommending one or more proposed courses of action.

Of course, that approach does not resolve the issue; it just kicks the can down the road until 2020. Yes, that is a presidential election year, so it could become more a political issue than a scientific one. But the politicians will need to deal with the scientific judgments contained in the report, and maybe a full national debate over them is not such a bad idea.

Worried that the commissioner might decide that marijuana is — or is not — a safe and effective drug? Don’t be. If science should be our guide, we first have to know what science thinks.

Only Congress can move marijuana out of Schedule I of the Controlled Substances Act. But lawmakers would be irresponsible if they were to make that call without first hearing from the nation’s finest scientific minds. Congress should listen, think and debate before acting.