Möller is also well known for his contributions to the laryngeal theory.

In 1878, Ferdinand de Saussure, then a 21-year-old student at the University of Leipzig, published his Mémoire sur le système primitif des voyelles dans les langues indo-européennes, 'Dissertation on the original system of vowels in the Indo-European languages', the work that founded the laryngeal theory. According to Saussure,