to E. Study's "Methoden zur Theorie der ternaren Formen" Study's "Ternary Fonns" presents a view of classieal invariant theory that remains little known to this day, and that deserves attentive reading. When the book was published, the combinato rial investigations of Gordan and of the English school were in their heyday. Hilbert's sweeping finiteness results were not yet available, and the term "algebraie geometry" had yet to take hold. Study's goals were geometrie rather than algebraie. He viewed the symbolic method as an algebraic machinery for the description of geometrie properties, and...