Mémoire sur le système primitif des voyelles dans les langues indo-européennes

Nineteenth-century comparativists had found regular alternations among the vowels of related Indo-European languages, but some patterns, such as the varying vowels in certain verbal roots, resisted tidy explanation. Saussure proposed that these irregularities could be accounted for by treating the original vowel system as more uniform than it appears, with variation introduced by additional elements that later disappeared or changed the surrounding vowels. His strategy was to explain the surviving diversity by reconstructing a simpler, more systematic source, an approach that treated the proto-language as a structured whole rather than a list of correspondences.

Saussure used the term for two hypothesised elements in Proto-Indo-European that, in his analysis, combined with other sounds to produce the long vowels and certain other vowel qualities seen in the daughter languages. No language attested them directly, so he inferred their existence from the structure of the system. Later scholars developed these ideas into what is now called laryngeal theory, in which the elements are understood as consonants of a laryngeal type. The concept matters because it is a rare case of a reconstructed sound posited on structural grounds and later given independent support.

In the 1920s Jerzy Kuryłowicz identified sounds in Hittite that corresponded to elements Saussure had posited, which was widely taken as confirming the central insight that unattested elements could be recovered from internal structure. The confirmation was not a complete vindication of the Mémoire's details, since later laryngeal theory modified the number, nature, and effects of the elements. Still, the episode is one of the most cited examples of a prediction in historical linguistics, and it gave Saussure's early reasoning lasting prestige.

The Mémoire is a work of comparative philology, not of general theory, yet many commentators see in it an early instance of thinking in terms of a system whose elements are defined by their relations. The reconstruction of the vowel system works by asking what the structure requires, not by cataloguing observed forms. That habit of mind is often linked to the relational account of value in the Course in General Linguistics, though scholars caution that the link is an interpretive reading and the book itself offers no explicit general theory.

The reception of the Mémoire is a documented part of Saussure's biography. It appeared when he was in his early twenties and was judged by some contemporaries to be highly original and by others to be too bold or poorly credited, and the circumstances of its reception are often discussed in accounts of his early career. Because accounts differ in detail, readers should consult a scholarly biography or critical history for specifics instead of relying on summary claims about who endorsed or rejected it and when.

A frequent misconception is that Saussure discovered the laryngeals in their modern form. He proposed the structural elements and an analysis of their effects, but the identification of laryngeal consonants, the subsequent refinement of the theory, and the link to Hittite came from later scholarship. Another misconception treats the book as an early version of structuralism. It is better described as a work of comparative reconstruction whose method resembles systemic thinking, and the connection to his later theory is a retrospective interpretation.