Open almost any comparative linguistics textbook and you’ll find a symbol used constantly: a small asterisk (*) placed before a word, as in “Proto-Indo-European *bʰréh₂tēr (brother).” Schleicher was the first to use this notation systematically.
The moment of invention, in two lines
In a footnote to a passage on Sanskrit phonology, Schleicher writes:
* bezeichnet erschloßene formen; bei den formen der indogermanischen Ursprache haben wir diese bezeichnung als überflüßig hinweg gelaßen.
(The asterisk (*) marks reconstructed forms; for the forms of the Indo-European parent language, we have omitted this mark as superfluous.)
Two important pieces of information sit inside this single sentence. First, the asterisk was introduced to mark a form “arrived at through comparison” — not one actually attested in a text. Second, and interestingly, Schleicher himself states plainly that he did not mark Proto-Indo-European forms in this book with an asterisk — because, in his view, it was so self-evident that every Proto-Indo-European form was a reconstruction that marking each one individually seemed redundant.
Why this symbol was needed
Comparative grammar before Schleicher — recall Bopp’s and Rask’s work — was mainly concerned with showing correspondences among languages that actually exist: Sanskrit, Greek, Latin, Gothic, and so on. All of these are “visible” languages, attested in real texts.
But once you’ve traced those correspondences, an obvious question follows: what did the ancestor of all of them — a “parent language” no longer preserved in any text — actually look like? Schleicher confronted this question directly. He needed a way to mark, at the level of notation itself, the difference between a form actually attested in a text and a form reconstructed through comparison as “what the parent language’s form must have been.” That need is exactly what gave rise to the asterisk.
A symbol still alive today
When a modern linguist writes a Proto-Indo-European word, they always add the asterisk — as in “*ph₂tḗr (father).” That convention is the direct descendant of the idea Schleicher laid out in this footnote. Schleicher himself chose to omit the asterisk from Proto-Indo-European forms specifically, but the generations after him refined this invention in exactly the opposite direction — toward “never omit it, always mark it.” Distinguishing an attested fact from a hypothesis built on inference, at the level of the symbol itself, is a remarkably simple idea — and more than 150 years later, it remains the field’s standard notation.
Summary
| Point | Detail |
|---|---|
| The quote | The asterisk (*) was introduced to mark a form “arrived at through inference” |
| Schleicher’s own practice | He omitted the asterisk from Proto-Indo-European forms as redundant |
| Legacy | Modern comparative linguistics marks every reconstructed Proto-Indo-European form with an asterisk — precisely where Schleicher chose to omit it |
In a nutshell — a symbol Schleicher judged safe to leave out, later generations polished into one that must never be left out. The asterisk still lives on at the fingertips of every comparative linguist.