About John Fearn's life and education not much is known. According to the Dictionary of National Biography, he started devoting himself primarily to philosophy after his retirement from the Royal Navy, but no source is given for this information. He published several works mainly on visual perception and metaphysics. He was a friend of Samuel Parr and Basil Montagu (philosophical writer and editor of Bacon) and died in Chelsea on 3 December 1837.
From The Continuum Encyclopedia of British Philosophy in Oxford Reference.