which she had never seen him before, cheerful or sad according to her
mood. This she could not do by aid of memory alone; she could not vary
the impress of her boy left on the brain; she could not vividly
reproduce it in shifting, rapidly successive conditions; she could not
modify and diversify that impress; in a word, she could not liberate
it. Memory could only re-give her, with single, passive fidelity, what
she had seen, unmodified, motionless, unenlivened, like a picture of
her boy on canvas. Urge intellectual activity to the phase above
memory, and the mental image steps out from its immobility, becomes a
changeful, elastic figure, brightened or darkened by the lights and
shadows cast by the feelings; the intellect, quick now with plastic
power, varying the image in position and expression, obedient
to the demands of the feelings, of which it is ever the ready
instrument. This third process is _imagination_.

Through this mode of intellectual action the materials gathered in the
mind are endlessly combined and modified. In all intellectual
activity, beyond bare perception and memory, imagination in some
degree is and must be present. It is in fact the mind handling its
materials, and in no sphere, above the simplest, can the mind move
without this power of firmly holding and molding facts and relations,
phenomena and interior promptings and suggestions. To the forensic
reasoner, to the practical master-worker in whatever sphere, such a
power is essential not less than to the ideal artist or to the weaver
of fictions. Imagination is thus the abstract action, that is, the
most intense action, of the intellect.

When I run over in my mind, and in the order of their service, the
first seven presidents of the United States, Washington, Adams,
Jefferson, Madison, Monroe, Adams, Jackson, I exert only memory. The