"There are certain tricks of the trade the movie will outgrow. It will surely outgrow, for instance, that trick technically known as the 'cut back,' which shifts the scenes back and forth in the irresponsible and mischievous manner of the dancing spot of light reflected from the mirror in a small boy's hand. The film director, flushed with the realization that he could move about with a freedom unknown to the stage, has been so delighted with this liberty that he has indulged himself incontinently, without pausing to consider that he might be playing havoc with the precious element called tension. It is easy to predict that the cut back, and similar evidences of restlessness, will fade gradually from the screens."
The New York Times' April 1915 review of Birth of a Nation.