Having successively studied Semitic languages, he began to make a name as an orientalist, and between 1787 and 1791 deciphered the Pahlavi inscriptions of the Sassanid kings.

He published the following Arabic textbooks:[4] In 1806 he added the duties of Persian professor to his old chair, and from this time onwards his life was one of increasing honour and success, broken only by a brief period of retreat during the Hundred Days.

With Abel Rémusat, he was joint founder of the Société asiatique, and was inspector of oriental typefaces at the Imprimerie nationale.

[4] In 1821 he was elected a member of the American Antiquarian Society[6] Silvestre de Sacy was the first Frenchman to attempt to read the Rosetta Stone.

[9] There was also considerable rivalry between Champollion and Thomas Young, an English Egyptology researcher active in hieroglyphic decipherment.

Early on, in 1802, Åkerblad published his version of the Demotic alphabet; sixteen of these letters later proved to be correct and were used by Champollion, as well as by Young.

Nevertheless, when, in spite of all adversity, Champollion had made big progress in decipherment by 1822—resulting in his Lettre à M. Dacier—Sacy cast all politics aside and warmly welcomed the good work of his student.

[4] Edward Said and other modern scholars have given critical attention to the theoretical foundations of "orientalism" in works like Chrestomathie arabe.

[11] In Edward Said's Orientalism, Sacy is described as "the teacher of nearly every major Orientalist in Europe, where his students dominated the field for about three-quarters of a century.

In a statistical overview derived from writings by and about Antoine Isaac Silvestre de Sacy, OCLC/WorldCat encompasses roughly 1,000+ works in 1,000+ publications in 16 languages and 3,000+ library holdings.