In June 1802 he arrived in Paris, where he lived in the house formerly owned by Baron d'Holbach and joined a circle including Heinrich Christoph Kolbe. He lectured on philosophy in private courses for Sulpiz Boisserée, and under the tutelage of Antoine-Léonard de Chézy and linguist Alexander Hamilton he continued to study Sanskrit and the Persian language. He edited the journal "Europa" (1803), where he published essays about Gothic architecture and the Old Masters. In April 1804 he married Dorothea Veit in the Swedish embassy in Paris, after she had undergone the requisite conversion from Judaism to Protestantism. In 1806 he and his wife went to visit Aubergenville, where his brother lived with Madame de Staël.