While some of his notions are long discredited, portions of his work have been valuable to later scholars, and Kircher helped pioneer Egyptology as a field of serious study.All medieval and early modern attempts were hampered by the fundamental assumption that hieroglyphs recorded ideas and not the sounds of the language.Monumental use of hieroglyphs ceased after the closing of all non-Christian temples in 391 by the Roman Emperor Theodosius I; the last known inscription is from Philae, known as the Graffito of Esmet-Akhom, from 394. 5th century) appears to retain some genuine knowledge about the writing system. Some are identified correctly, such as the "goose" hieroglyph (zꜣ) representing the word for "son".
As no bilingual texts were available, any such symbolic 'translation' could be proposed without the possibility of verification.
The breakthrough in decipherment came only with the discovery of the Rosetta Stone by Napoleon's troops in 1799 (during Napoleon's Egyptian invasion).
By the Greco-Roman period, there are more than 5,000.
Instead, it is pointed out and held that "the evidence for such direct influence remains flimsy” and that “a very credible argument can also be made for the independent development of writing in Egypt..." Hieroglyphs consist of three kinds of glyphs: phonetic glyphs, including single-consonant characters that function like an alphabet; logographs, representing morphemes; and determinatives, which narrow down the meaning of logographic or phonetic words.
Hieroglyphic writing was not, however, eclipsed, but existed alongside the other forms, especially in monumental and other formal writing.