Above: Part one (of nine) of Der Student von Prag (1926). Direct YouTube link here.

How, in a flash, that had brought back the old days of the cinema, he thought, indeed his own delayed student days, the days of the Student of Prague... – UTV, p 305.

There were three versions of Der Student von Prag: 1913, directed by Stellan Rye, with Paul Wegener; 1926, directed by Henrik Galeen, with Conrad Veidt and Werner Krauss (the one Laruelle has in mind); and 1936, directed by Arthur Robison.

Based on the Faust legend and Poe's ‘William Wilson’, the film concerns a student named Baldwin, who has sold his reflection to a sorcerer, Scapinelli, and who becomes a social outcast when his mirror image slays in a duel a man whose life Baldwin had promised to spare. Baldwin buys back his soul at the cost of his own life and shoots his mirror image, thereby killing himself in a displaced form of suicide.