Retired Supreme Court Justice John Paul Stevens on Thursday said the federal government should legalize marijuana.

"Yes," Stevens, 94, replied after NPR host Scott Simon asked him whether it should be his radio show. [LISTEN HERE]

"I really think that that's another instance of public opinion [that's] changed. And recognize that the distinction between marijuana and alcoholic beverages is really not much of a distinction,” he added.

The public generally thinks the prohibition of alcohol is not worth the cost, Stevens said.

“And I think really, in time, that will be the general consensus with respect to this particular drug."

In 2005, when Stevens was still on the Supreme Court, the justices ruled in Gonzales v. Raich that Congress could criminalize the production and use of homegrown pot, even in states where they’ve approved medical marijuana. 

Stevens’s statement is not unexpected given he was considered a member of the high court’s liberal side. 

Republican President Gerald Ford, however, nominated Stevens in 1975, and Stevens considers himself a conservative.

The retired judge has been promoting his new book, Six Amendments, in which he proposes six changes to the Constitution.

The federal government should get rid of capital punishment, curb the right to bear arms and limit the amount of corporate money fed into elections, he writes in the book.

On NPR, when Stevens was asked about gay marriage, he said, "in due course when people actually think through the issues they will be able to accept merits of my arguments."

Stevens retired in 2010, and President Obama nominated Justice Elena Kagan to succeed him.