Robert Blanché died in 1975. Nine years before, in 1966, he published with Vrin: Structures intellectuelles. Therein, he deals with the logical hexagon. Whereas the logical square or square of Apuleius represents four values: A, E, I, O, the logical hexagon represents six, that is to say, not only A, E, I, O but also two new values: Y and U. It is advisable to read the article: logical hexagon as well what concerns Indian logic.
In La Logique et son histoire d' Aristote à Russell, published with Armand Colin in 1970, Robert Blanché, the author of Structures intellectuelles (Vrin, 1966) mentions that Józef Maria Bocheński speaks of a sort of Indian logical triangle to be compared with the square of Aristotle (or square of Apuleius), in other words with the square of opposition.
Works
La Notion de fait psychique, essai sur les rapports du physique et du mental – 1934, ed. PUF.
Le Rationalisme de Whewell – 1935, ed. PUF.
Whewell : de la construction de la science – 1938, ed. J. Vrin
La Science physique et la réalité : réalisme, positivisme, mathématisme - 1948, ed. PUF