Robert Downey Jr. is donning blackface make-up in the new Ben Stiller comedy, “Tropic Thunder.” Publicity photos show the actor, widely regarded as one of the most gifted in Hollywood, looking convincing and unrecognizable as an African-American; in a convoluted ploy to create an opportunity for Downey to take on the challenge, he plays a Downey-like white “Method actor” who is obsessive about playing a black character. Not surprisingly, and almost certainly intentionally, the casting of Downey has hit several raw nerves. It is an edgy choice, a controversial one, and, the filmmakers hope, funny. But is it wrong?

Downey’s stunt cannot be evaluated without reflecting on the history of blackface in America. In the first forty years of the 20^th century, white performers appearing in exaggerated make-up both ridiculed blacks and kept them out of work. Even though there are famous films that show such stars as Al Jolson, Bing Crosby, Mickey Rooney and Fred Astaire performing entertainingly in blackface, it has come to represent the height of bad taste and racial insensitivity. Blackface make-up is a symbol of Jim Crow, segregation, and the denigration of the black race in the United States.

But actors act. There must be no role an actor can be forbidden to play in a free society. Men play women in plays and movies. Women have played Hamlet on Broadway. Young actors play old men, like Dustin Hoffman in “Little Big Man.” Middle-aged actors play teenagers, as anyone who has seen “Grease” will attest. Slim actresses like Gwyneth Paltrow play morbidly obese women. Female Hillary Swank won an Oscar playing a teenage boy. Linda Hunt won an Oscar playing a Cambodian man. With the use of digital manipulation, actors with two legs can play actors with one leg or none; with trick camera shots, normal-sized actors can portray dwarves, giants, or hobbits. Why is race any different?

In short, it isn’t, or shouldn’t be.

The arguments leveled against casting white actors to play individuals of other races are financial and political rather than artistic. The most common one was leapt upon by the industry blog “Just Jared” as soon as the Downey casting became known. “I’m not black and I find it offensive,” he wrote. “Are there not any talented enough black actors out in the world that they feel the need to hire a white guy to do a black guy?” But that’s a false objection. If the producers believe that watching Robert Downey convincingly play a black character has special entertainment value, then obviously it is not merely a substitute for hiring a competent black actor. In “Murder on the Orient Express,” a fit and youthful-looking Albert Finney, with a full head of hair, was cast to play the much older, bald, paunchy Belgian detective Hercule Poirot, with a meticulous accent. Of course there were plenty of talented older character actors who could have done the part well and without requiring padding, latex, and hours in the make-up chair. The film was not suggesting otherwise. But part of the rationale was to give Finney an acting challenge, which he discharged brilliantly and attracted a great deal of publicity doing so. The casting of Downey has the same objective, even though the scriptwriter (or Downey) thought they could finesse the controversy by having Downey play a white actor playing a black character, rather than having Downey just play a black character.

This is what lawyers call “a distinction without a difference.” I’d be willing to wager that the part was written for a black actor, then re-envisioned once Downey became a candidate for the role. The part could easily have been re-written as white. If that had happened, nobody would be complaining, though the effect on the African American acting pool would be identical. There is no doubt that black actors do not have enough roles in Hollywood films, and that the industry has a long record of excluding them from roles large and small. Undoubtedly, some activists will use Downey’s casting to focus public attention on that issue, but it has little to do with Downey. The ethics of casting allow an infinite number of considerations in the casting process, including name recognition, publicity, the special qualities a particular actor may bring to a role, the audience’s enjoyment in seeing a part cast against type (Monte Python’s John Cleese was cast as a Western sheriff in “Silverado;” presumably “Jared” felt this was an implied insult to all the grizzled American actors. Well, it wasn’t. It was just funny and interesting casting.), and many, many other factors. Giving a part to a qualified African American actor for employment equity purposes is certainly one possible factor in a casting decision, but it is not an ethically mandatory one. Ultimately, in all artistic projects, the primary consideration has to be what will result in the best product. On that basis, the casting of Downey is defensible.

The second indictment is that allowing a white actor to use black make-up stirs up offensive memories of the history of the device. And it does. But the fact that an artistically defensible casting choice bears a superficial resemblance to a racist tradition long-deplored and discarded does not make it unethical. In a 21^st century America that is finally making strides toward a society where everything is not dictated by racial grievances, separations and preferences, any actor of any race is free to portray anyone and anything without political condemnation. The only legitimate factor in determining whether a particular piece of casting was the right choice must be this:

Did it result in a good performance?

The more audacious the challenge, the tougher the standard that will be applied. Downey better be damned good. But he has the right, and is right, to try.