Imagination penetrative is concerned, not with the combining, but the apprehending of things

Thus far we have been defining that combining operation of the Imagination, which appears to be in a sort mechanical, yet takes place in the same inexplicable modes, whatever be the order of conception submitted to it, though I choose to illustrate it by its dealings with mere matter before taking cognizance of any nobler subjects of imagery. We must now examine the dealing of the Imagination with its separate conceptions, and endeavour to understand, not only its principles of selection, but its modes of apprehension with respect to what it selects.

Milton's and Dante's description of flame

When Milton's Satan first “rears from off the pool his mighty stature,” the image of leviathan before suggested not being yet abandoned, the effect on the fire-wave is described as of the upheaved monster on the ocean-stream.”

And then follows a fiercely restless piece of volcanic imagery: