Carl Hart is not your typical academic.

Trained as a neuroscientist and now a psychology professor at Columbia University,

in his research studies he brings heavy drug users into his lab for weeks at a time

to observe how drugs affect them and to learn about the decision making.

In his new book, Drug Use for Grownups, he argues for a radical overhaul of drug policy.

He's not just talking marijuana. In his ideal world, heroin, methamphetamines, cocaine,

they'd all be legal.

Welcome to People I Mostly Admire, with Steve Levitt.

I've been teaching undergraduates about drug policy for two decades,

and I definitely haven't been teaching them what Carl Hart advocates.

So I wonder whether he'll change my mind. He certainly thought a lot harder

about these issues than I have. I'm also deeply curious to see what he's like as a person.

He's incredibly open in his books, talking about harsh details of his life growing up,

and especially about his own extensive use of drugs.

My guess is that he's going to be a lot more fun than my usual guest.

All right, so let's start with a punchline. If you were in charge of drug policy in the

United States, and you could start completely from scratch, no constraints, what set of policies

towards currently illicit drugs would you put into place?

Well, the first thing I do is I would legally regulate the drugs that people seek from cocaine,

to heroin, to cannabis, to MDMA. People might have to pass a requirement like a driver's license

in order to purchase something like heroin and cocaine. I would also control a unit dose,

make sure that there's not enough in a product, to kill people when we're dealing with the illicit

...