thoughts and he will be surprised to find how rare and indistinct in
general are the images of objects which arise before his mind. If he
says "I shall take a cab and get to the railway by the shortest cut,"
it is ten to one that he forms no image of cab or railway, and but a
very vague image of the streets through which the shortest cut will
lead. Imaginative minds see images where ordinary minds see nothing but
signs: this is a source of power; but it is also a source of weakness;
for in the practical affairs of life, and in the theoretical
investigations of philosophy, a too active imagination is apt to
distract the attention and scatter the energies of the mind.

In complex trains of thought signs are indispensable. The images, when
called up, are only vanishing suggestions: they disappear before they
are more than half formed. And yet it is because signs are thus
substituted for images (paper transacting the business of money) that
we are so easily imposed upon by verbal fallacies and meaningless
phrases. A scientific man of some eminence was once taken in by a wag,
who gravely asked him whether he had read Bunsen's paper on the
MALLEABILITY of light. He confessed that he had not read it: "Bunsen
sent it to me, but I've not had time to look into it."

The degree in which each mind habitually substitutes signs for images
will be, CETERIS PARIBUS, the degree in which it is liable to error.
This is not contradicted by the fact that mathematical, astronomical,
and physical reasonings may, when complex, be carried on more
suecessfully by the employment of signs; because in these cases the
signs themselves accurately represent the abstractness of the
relations. Such sciences deal only with relations, and not with
objects; hence greater simplification ensures greater accuracy. But no
sooner do we quit this sphere of abstractions to enter that of concrete