Here is a brilliant example of poetic imagination, the intellect urged to its finest action to satisfy the feeling which delights in the grand, the select, the beautiful.

  “Silent, upon a peak in Darien.”

What an outlook!  What a solemn, mysterious, elevating inward moment it creates in us!  To ascend to that peak, to carry the reader thither with him, that is the flight of a great poet, of one who has been—­as in that choice poem, “The Prelude,” Wordsworth, with an electric stroke of poetic imagination, says of Newton—­

  “Voyaging through strange seas of thought, alone.”

This vigor of flight in the poet, bearing on his wing the reader, whom he ushers to new, sudden vistas, is a test of poetic genius.  Some poets never carry you to heights, but rather make you feel while reading them as if you were moving through shut-in valleys:  their verse wants sky.  They are not poetically imaginative, are not strung for those leaps which the great poet at times finds it impossible not to make.  They have more poetic fancy than poetic imagination.  Poetic fancy is a thin flame kindled deliberately with gathered materials; poetic imagination is an intense flash born unexpectedly of internal collisions.  Fancy is superficial and comparatively short-sighted; imagination is penetrative and far-sighted, bringing together things widely sundered, apparently diverse and opposite.  Fancy divides, individualizes; imagination compounds, builds, globes.  Fancy is not so broad or so keen or so warm or so bounding as imagination; is comparatively tame and cold and quiet.  Imagination is synthetical.  Large exhibitions of poetic imagination are rare even in the greatest poets.  At its best it strikes deep into the nature of things, has a celestial quality which invests it with awe.  Spenser shows great resources of fancy, but little imagination.  The arc of imagination is in him too near its center.  Hence there is no reach in his thoughts.  He has no exhaustless depths within.  He is not, as Coleridge says Shakespeare is, an example of “endless self-reproduction.”  Cowley, says the same great critic, “is a fanciful writer, Milton an imaginative poet.”

As I have already said, the power of imagining, of forming in the mind images, conceptions, is a purely intellectual power, and imagination becomes poetical only when this intellectual power is an agent obeying that emotional power which ardently seeks, intensely longs for, the better, the more perfect, the purer, in one word, the beautiful in each province of multiform life.  The willing agent, intellect, is sent out on excursions of discovery, and unexpectedly falls in with and captures all kinds of sparkling booty.

Writers weak in poetic imagination are not visited by those beaming thoughts that come unsummoned out of the invisible, like new stars which, out of the unfathomable deeps of the sky, dart suddenly upon the vision of the heaven-watcher.  Such writers deal with the known, with the best commonplace, not the common merely; and under the glance of genius the common grows strange and profound.