But in comparing ancient with modern imaginative literature, certain changes especially strike us, and chief among them a stronger infusion of sentiment and what we call the picturesque.  I shall endeavor to illustrate this by a few examples.  But first let us discuss imagination itself, and give some instances of its working.

“Art,” says Lord Verulam, “is man added to Nature” (homo additus naturae); and we may modernize his statement, and adapt it to the demands of aesthetics, if we define art to be Nature infused with and shaped by the imaginative faculty of man; thus, as Bacon says elsewhere, “conforming the shows of things to the desires of the mind.”  Art always platonizes:  it results from a certain finer instinct for form, order, proportion, a certain keener sense of the rhythm there is in the eternal flow of the world about us, and its products take shape around some idea preexistent in the mind, are quickened into life by it, and strive always (cramped and hampered as they are by the limitations and conditions of human nature, of individual temperament, and outward circumstances) toward ideal perfection—­toward what Michelangelo called

Ideal form, the universal mould.

Shakespeare, whose careless generalizations have often the exactness of scientific definitions, tells us that

The lunatic, the lover, and the poet,
Are of imagination all compact;

that

              as imagination bodies forth
  The forms of things unknown, the poet’s pen
  Turns them to shapes, and gives to airy nothing
  A local habitation and a name.

And a little before he had told us that

Lovers and madmen have such seething brains,
Such shaping fantasies, that apprehend
More than cool reason ever comprehends.

Plato had said before him (in his “Ion”) that the poet is possessed by a spirit not his own, and that he cannot poetize while he has a particle of understanding left.  Again he says that the bacchantes, possessed by the god, drink milk and honey from the rivers, and cannot believe, till they recover their senses, that they have been drinking mere water.  Empedocles said that “the mind could only conceive of fire by being fire.”

All these definitions imply in the imaginative faculty the capabilities of ecstasy and possession, that is, of projecting itself into the very consciousness of its object, and again of being so wholly possessed by the emotion of its object that in expression it takes unconsciously the tone, the color, and the temperature thereof.  Shakespeare is the highest example of this—­for example, the parting of Romeo and Juliet.  There the poet is so possessed by the situation, has so mingled his own consciousness with that of the lovers, that all nature is infected too, and is full of partings: 

  Look, love, what envious streaks
  Do lace the severing clouds in yonder east.