There was a time when the word “liberal” meant something closer to what we currently mean when we say “libertarian.” This should not be surprising, since the root word of both is “liberty.” Unfortunately, the definition of “liberal” has drifted—and various liberal ideals have drifted along with it. Take rights, for example. Liberals from John Locke to Thomas Jefferson have always been known for their advocacy for people’s rights. In their time, the word “rights” referred to things that it is wrong to forcibly prevent someone from doing. Nowadays, the word often refers instead to anything the...