It is true that our modern sense of the continuity of history has shown us that neither in politics nor in nature are there revolutions ever but evolutions only, and that the prelude to that wild storm which swept over France in ’89 and made every king in Europe tremble for his throne, was first sounded in literature years before the Bastille fell and the Palace was taken.  The way for those red scenes by Seine and Loire was paved by that critical spirit of Germany and England which accustomed men to bring all things to the test of reason or utility or both, while the discontent of the people in the streets of Paris was the echo that followed the life of Emile and of Werther.  For Rousseau, by silent lake and mountain, had called humanity back to the golden age that still lies before us and preached a return to nature, in passionate eloquence whose music still lingers about our keen northern air.  And Goethe and Scott had brought romance back again from the prison she had lain in for so many centuries—­and what is romance but humanity?

Yet in the womb of the Revolution itself, and in the storm and terror of that wild time, tendencies were hidden away that the artistic Renaissance bent to her own service when the time came—­a scientific tendency first, which has borne in our own day a brood of somewhat noisy Titans, yet in the sphere of poetry has not been unproductive of good.  I do not mean merely in its adding to enthusiasm that intellectual basis which is its strength, or that more obvious influence about which Wordsworth was thinking when he said very nobly that poetry was merely the impassioned expression in the face of science, and that when science would put on a form of flesh and blood the poet would lend his divine spirit to aid the transfiguration.  Nor do I dwell much on the great cosmical emotion and deep pantheism of science to which Shelley has given its first and Swinburne its latest glory of song, but rather on its influence on the artistic spirit in preserving that close observation and the sense of limitation as well as of clearness of vision which are the characteristics of the real artist.

The great and golden rule of art as well as of life, wrote William Blake, is that the more distinct, sharp and defined the boundary line, the more perfect is the work of art; and the less keen and sharp the greater is the evidence of weak imitation, plagiarism and bungling.  ’Great inventors in all ages knew this—­Michael Angelo and Albert Durer are known by this and by this alone’; and another time he wrote, with all the simple directness of nineteenth-century prose, ’to generalise is to be an idiot.’