It's in business language, though, that Mad Men really shows its weaknesses. Modern boardroom language creeps in with striking regularity. Take the verb "leverage," for example. Last season, Pete Campbell angrily reported that Philip Morris used Sterling-Cooper "to leverage a sweeter deal" from another agency. Leverage presumably sounded like a hard-nosed business term in the table read; but it comes from banking, and hard as it may be to remember, investment bankers did not always rule the roost of American business. Widespread use of "to leverage" metaphorically is a creation of Reagan's America, not Kennedy's. Don Draper and his peers in grey flannel suits looked out on a dull, relatively unimportant banking sector; for them, leverage meant debt as much as it meant power. Not only is the individual phrase wrong; so is the whole field of metaphor. Talking like an investment banker would have had approximately the allure of talking like an accountant.

Business vernacular seems to trip up the writers again and again. Draper's new contract in season three includes a "signing bonus," a phrase that was extremely rare outside of sports (the staid "bonus for signing" was far more common); Paul Kinsey is urged to "keep a low profile" at a meeting in 1963, a phrase that spread like wildfire only in 1969; and in season four Honda sets a series of rules to "even the playing field" in a competition, a phrase that (along with the more common "level the playing field") seems to have entered the boardroom around 1977.

It's not only business, though. There are scores of idioms that are strikingly modern. "Feel good about," "match made in heaven," "tough act to follow," "make eye contact," "fantasize about"; all are at least tenfold more common today than in Mad Men's times. Any of these individually might be perfectly plausible; but for "feel good about," for example, to be said four separate times over the course of the show by several different characters is extraordinarily unlikely. Such flaws aren't just anecdotal; shows and movies from the 1960s, written by writers with as sure a grasp of the spoken language as Weiner, have far fewer outliers from the print corpus than their modern imitators. The Twilight Zone, for example, doesn't use "feel good about" once in over 100 episodes.

It may seem unfair to pick on Mad Men for its language inaccuracies; after all, Shakespeare's characters spoke highly untraditional English, and great shows like Deadwood routinely ran roughshod over any form of linguistic accuracy. But the careful balance of anachronism, in all its forms, is at the heart of the Mad Men's mechanics far more than Shakespeare's. We watch the show to revel in the foreignness of the recent past. The drinking, the smoking, the leering, and even the personal reserve all remind us that the modern world isn't the only one. (This can be a problem, as Benjamin Schwarz wrote in The Atlantic after season two; it can be hard to be enveloped in a world so deliberately off-putting.) Weiner even deliberately plays with anachronisms: At the very end of the show's first season, set in 1960, Don Draper returns home hoping to see his picture-perfect family in front of him. Instead he finds an empty house, and the season fades to black to Bob Dylan's "Don't Think Twice, It's All Right." It works perfectly well as a score for an abandoned husband; but knowing that the song wasn't released for another three years adds the weight of the shift in decades to Draper's plight. Weiner explained the choice to the Times as an attempt to outline the future of the show if it were cancelled.