Ioannis Psycharis

Ioannis Psycharis
Woodcut portrait of Jean Psychari in the Ποικίλη Στοά magazine from 1888
Born	15 May 1854 Odessa, Russian Empire
Died	29 September 1929 Paris, France
Occupation	Author
Spouse(s)	Noémie Renan
Relatives	Ernest Renan (father-in-law)

Ioannis (Yannis) Psycharis (Greek: Ιωάννης (Γιάννης) Ψυχάρης; French: Jean Psychari; 15 May 1854–29 September 1929) was a French philologist of Greek origin, author and promoter of Demotic Greek.

Psycharis was born on 15 May 1854 in Odessa (in modern-day Ukraine, then part of the Russian Empire). His mother died when he was a child, and he was raised by his grandmother in Marseille. He also spent some time with his father in Constantinople and later moved to Paris.

He studied at the École des langues orientales.

Psycharis was director of studies at the École pratique des hautes études after 1885, and then professor at the École des langues orientales from 1903 to 1928, succeeding Émile Legrand ().

In 1886, he made a trip to Greece out of which he wrote My Journey, advocacy of the Demotic Greek language. He then became the mentor of the Demotic side in the Greek language question.

Psycharis was the populariser of the term diglossia, which describes a language community's simultaneous use of the genuine mother tongue of the present day, the vernacular, and a dialect from centuries earlier in the history of the language. The vernacular is of low prestige and is discouraged or totally forbidden for written use and formal spoken use, while the obsolete dialect is of high prestige and is used for most written communication and for formal speeches by institutions of authority such as government and religious institutions. Diglossia was a major issue in Greek society and politics in the 19th and 20th centuries (see Greek language question).