Known as "Walking" Stewart to his contemporaries for having travelled on foot from
Madras,
India (where he had worked as a clerk for the
East India Company) back to Europe between 1765 and the mid-1790s, Stewart is thought to have walked alone across Persia,
Abyssinia, Arabia, and Africa before wandering into every European country as far east as Russia. Over the next three decades Stewart wrote prolifically, publishing nearly thirty philosophical works, including
The Opus Maximum (London, 1803) and the long verse-poem
The Revelation of Nature (New York, 1795). In 1796,
George Washington's portrait-painter,
James Sharples, executed a pastel likeness of Stewart for a series of portraits which included such sitters as
William Godwin,
Joseph Priestley, and
Humphry Davy, suggesting the intellectual esteem in which Stewart was once held. After his travels in East India, Stewart became a
vegetarian. He was also a
teetotaler. ==Philosophy==