Therefore, medico-legal experts were the first to become interested in the scientific study of sexuality in the 19th century.Auguste Ambroise Tardieu (1818-1879) published his (1857).As such, he argued, it should come under psychiatric care rather then legal prosecution.
The term "sexual inversion" was popularized in English with the publication of a book of the same title written by sexologist Havelock Ellis (1859-1939) and his homosexual collaborator John Addington Symonds (1840-1893).
The European decriminalization of sodomy began in post-Revolutionary France.
The Constituent Assembly abrogated laws criminalizing "crimes against nature" in 1791 when it abolished ecclesiastical courts.
This followed from the broader spirit of Enlightenment legal reform that protected the private sphere from state intrusion.
The public and minors were still deemed to require state protection; therefore, the Law of 19-22 July 1791 and the Napoleonic Penal Code of 1810 criminalized "debauchery or corruption" of minors of either sex and "offenses against public decency" including sex in public places such as parks or bathrooms.