Upon any work, and especially upon a play, a great number of patterns of increasing generality will fit equally well, as more and more of the incident is left out. As respects infringement of copyrights in plays, the controversy chiefly centers upon the characters and sequence of incident, these being the substance. Otherwise the playwright could prevent the use of his ideas, to which, apart from their expression, his property is never extended.
The plaintiff is the author of a play, "Abie's Irish Rose," which it may be assumed was properly copyrighted under section five, subdivision (d), of the Copyright Act, 17 USCA § 5(d). The defendant produced publicly a motion picture play, "The Cohens and The Kellys," which the plaintiff alleges was taken from it. Plaintiff alleged that the copyright in her play, concerning a marriage between a Jewish man and an Irish woman and the resulting difficulties between both families, was infringed by defendant's movie about the marriage of an Irish man and a Jewish woman, also focusing on differences between their families. The court affirmed the judgment for defendant, finding the two stories were different as to incident and character, and thus there was no infringement. As for plots, the only matter common to the two was a quarrel between a Jewish father and an Irish father, the marriage of their children, the birth of grandchildren, and a reconciliation. The court found such theme was only a part of plaintiff's ideas, and therefore was not copyrightable.
Is there an existence of infringement in this case?
The Court found that the plot of the second play was too different to infringe, because the most detailed pattern, common to both, eliminated so much from each that its content went into the public domain; and for this reason we said, "this mere subsection of a plot was not susceptible of copyright." But the Court does not doubt that two plays may correspond in plot closely enough for infringement. How far that correspondence must go is another matter. Nor does the court need to hold that the same may not be true as to the characters, quite independently of the "plot" proper, though, as far as we know, such a case has never arisen. If Twelfth Night were copyrighted, it is quite possible that a second comer might so closely imitate Sir Toby Belch or Malvolio as to infringe, but it would not be enough that for one of his characters he cast a riotous knight who kept wassail to the discomfort of the household, or a vain and foppish steward who became amorous of his mistress. These would be no more than Shakespeare's "ideas" in the play, as little capable of monopoly as Einstein's Doctrine of Relativity, or Darwin's theory of the Origin of Species. It follows that the less developed the characters, the less they can be copyrighted; that is the penalty an author must bear for marking them too indistinctly.