He also stated in Fingal that all the other works of Ossian had been lost. Nevertheless, he published the large work Temora the following year. The wide public acclaim which greeted the work of Ossian was soon tempered with suspicion of its authenticity. The controversies that raged in the 1760s and 1770s involved philosopher David Hume, poet David Gray and lexographer Dr Samuel Johnson. Scottish-English and Scottish-Irish literary hostilities arose. The epics have subsequently been translated into Italian (1763), German (1764), French (1774) and many other languages, the most recent being Japanese (1971) and Russian (1983). There was also a flood of books and pamphlets arguing the authenticity or dubiety of the Ossianic poems.

      James was urged to produce the Gaelic originals and though he made an effort to do this by exposing them for view at a London book seller's, they appear not to have been understood. The alternative was to publish the originals. This required work on editing them which James was not inclined to do. Instead he left money in his will for the publication of a Gaelic Ossian. Meanwhile the controversy raged on.

     The question of authenticity of the Ossian poems was examined by a committee of the Highland Society of London. The conclusion of their investigation filled a substantial volume which was published in 1805 and which can be summarized as follows:
           (1) the characters in the poems were not invented but were subjects of existing Gaelic tradition; and that genuine Gaelic poems, songs and ballads existed which might be termed "Ossianic", relating to a remote, prehistoric or mythical time.
           (3) Ossianic poetry and song had been committed to writing and were to be found in surviving manuscripts.

           (4) James Macpherson used Ossianic poems freely piecing them together with his own narrative and constructing them into longer poems or epics.