Sir James Thomas Knowles (13 October 1831 - 13 February 1908) was an English architect and editor. He was intimate with the poet Alfred, Lord Tennyson and the founder of the Metaphysical Society to seek rapprochement between religion and science.
James Knowles was born in London, the son of the architect James Thomas Knowles (1806-1884), and himself trained in architecture at University College and in Italy. Among the buildings he designed were three churches in Clapham, South London, Mark Masons' Hall, London (later the Thatched House Club), Lord Tennyson's house at Aldworth, the Leicester Square garden (as restored at the expense of Albert Grant), Albert Mansions, Victoria Street in Westminster, and an 1882 enlargement of the Royal Sea Bathing Hospital at Margate in Kent.
However, his preferences led him simultaneously into a literary career. In 1860 he published The Story of King Arthur. In 1866 he was introduced to Alfred Lord Tennyson and later agreed to design his new house on condition there was no fee. This led to a close friendship, Knowles assisting Tennyson in business matters, and among other things helping to design scenery for the play The Cup, when Henry Irving produced it in 1880.
Knowles corresponded with a number of the most interesting men of the day, and in 1869, with Tennyson's cooperation, he founded the Metaphysical Society, the object of which was to attempt some intellectual rapprochement between religion and science by getting the leading representatives of faith and unfaith to meet and exchange views. Members included Tennyson, Gladstone, W. K. Clifford, W. G. Ward, John Morley, Cardinal Manning, Archbishop Thomson, T. H. Huxley, Arthur Balfour, Leslie Stephen, and Sir William Gull. The society formed the nucleus of the distinguished list of contributors who supported Knowles in his capacity as an editor.
In 1870 he succeeded Dean Alford as editor of the Contemporary Review, but left it in 1877 owing to the objection of the proprietors to the insertion of articles (by W. K. Clifford notably) attacking Theism and founded the Nineteenth Century (to the title of which, in 1901, were added the words And After). Both periodicals became very influential under him, and formed the type of the new sort of monthly review which came to occupy the place formerly held by the quarterlies. For example, it was prominent in checking the Channel Tunnel project, by publishing a protest signed by many distinguished men in 1882. In 1904 he received a knighthood. He was a considerable collector of works of art.