Society who would become known for his hypothesis in 1786 regarding a relationship among European and Indo-Aryan languages, had been deeply wounded by Anquetil-Duperron's scornful treatment of Jones's countrymen and, in a pamphlet written in French in 1771, Jones dismissed Anquetil-Duperron's manuscripts as a fraud. Other scholars in England criticised Anquetil-Duperron's translation on philological grounds. In France, Voltaire poked fun at Anquetil-Duperron and his translation in his article "Zoroastre" (1772) in the Questions sur l'Encyclopédie. Diderot was likewise similarly "conspicuously disappointed". For these philosophes the ideas revealed by Anquetil-Duperron's translation seemed impossible to relate to the idealized Enlightenment-era view of Zoroaster or to his religion which they associated with simplicity and wisdom. Many German scholars, with the notable except of Herder, also attacked Anquetil-Duperron's translation. In 1820, fifteen years after his death, Anquetil-Duperron was vindicated by the Danish philologist Rasmus Rask. The debate would rage for another thirty years after that. Anquetil-Duperron's "attempt at a translation was, of course, premature", and, as Eugène Burnouf demonstrated sixty years later, translating the Avesta via a previous translation was prone to errors. However, Anquetil-Duperron was the first to bring an ancient oriental sacred text other than the Bible to the attention of European scholars. Later years Following his Zend Avesta and until his death in 1805, Anquetil-Duperron was occupied with studying the laws, history, and geography of India. "In his youth a kind of Don Juan; he now led the life of a poor, ascetic bachelor, combining Christian virtue with the wisdom of a Brahmin." During that period he abandoned society, and lived in voluntary poverty on a few pence a day. In 1778, he published at Amsterdam his , in which he endeavoured to prove that the nature of oriental despotism had been greatly misrepresented by Montesquieu and others. His appeared in 1786 and formed part of Thieffenthaler's Geography of India. In 1798, he published (Hamburg, 2 vols.), a work considered notable by the British for its "remarkable" invectives against them and for its "numerous misrepresentations". Anquetil-Duperron's most valuable achievement in his last years was the publication of the Oupnek'hat, id est, Secretum tegendum, a two-volume Latin retranslation and commentary of a Persian translation of fifty Upanishads. Duperron had received the Persian translation from India in 1775 and had translated that into both French and Latin, but the French translation was never published. The Latin translation was published in Strasbourg in 1801-1802