the details which will most powerfully affect us, without any
disturbance of the harmony of the general impression, does not depend
solely upon the vividness of his memory and the clearness with which
the objects are seen, but depends also upon very complex and peculiar
conditions of sympathy which we call genius. Hence we find one man
remembering a multitude of details, with a memory so vivid that it
almost amounts at times to hallucination, yet without any artistic
power; and we may find men--Blake was one--with an imagination of
unusual activity, who are nevertheless incapable, from deficient
sympathy, of seizing upon those symbols which will most affect us. Our
native susceptibilities and acquired tastes determine which of the many
qualities in an object shall most impress us, and be most clearly
recalled. One man remembers the combustible properties of a substance,
which to another is memorable for its polarising property; to one man a
stream is so much water-power, to another a rendezveus for lovers.

In the close of the last paragraph we came face to face with the great
difficulty which constantly arrests speculation on these matters--the
existence of special aptitudes vaguely characterised as genius. These
are obviously incommunicable. No recipe can be given for genius. No man
can be taught how to exercise the power of imagination. But he can be
taught how to aid it, and how to assure himself whether he is using it
or not. Having once laid hold of the Principle of Vision as a
fundamental principle of Art, he can always thus far apply it, that he
can assure himself whether he does or does not distinctly see the
cottage he is describing, the rivulet that is gurgling through his
verses, or the character he is painting; he can assure himself whether
he hears the voice of the speakers, and feels that what they say is
true to their natures; he can assure himself whether he sees, as in
actual experience, the emotion he is depicting; and he will know that