"Mr. Francis Osbaldistone is an innocent man, Rashleigh," said Miss Vernon, "and he demands an investigation of the charge against him, and I intend to support him in it." "You do, my pretty cousin?—I should think, now, Mr. Francis Osbaldistone was likely to be as effectually, and rather more delicately, supported by my presence than by yours." "Oh, certainly; but two heads are better than one, you know."
Two heads are better than one, sir. We will prosecute our investigations together.
2003 November 9, Nancy Meyers as told to Amy Barrett, “Sex and the Single Older Woman”, in New York Times[2], retrieved 25 February 2013:
Collaboration is great for screenwriting. It's not as simple as two heads are better than one, but if you find the right person, you can feed off each other.