ady mental eye, in order to see
the conclusion that is implicated in the premises. Without this, he
falls into confusion and fallacy, or fails, with the premises both
before him, to get the conclusion. The "clear and steady mental eye",
in less figurative language, means the ability to check hasty
responses to either premise alone, or to extraneous features of the
situation, so as to insure that "unitary response" to the combination
of premises which constitutes the perceptive act of inference.

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EXERCISES

1. Outline the chapter.

2. In what respects does the animal's solution of a problem fall
short of reasoning?

3. Give a concrete instance of reasoning belonging under each of
the types mentioned in the text.

4. How is it that superstitions such as that of Friday being an
unlucky day persist? What would be the scientific way of testing
such a belief?

5. What causes tend to arouse belief, and what to arouse doubt?

6. Introspective study of the process of thinking. Attempt to
solve some of the following problems, and write down what you can
observe of the process.

(a) What is it that has four fingers and a thumb, but no flesh
or bone?

(b) Why does the full moon rise about sunset?

(c) If a book and a postage stamp together cost $1.02, and
the book costs $1.00 more than the stamp, how much does the
stamp cost?

(d) A riddle: "Sisters and brothers have I none, yet this
man's father is my father's son."

(e) Prove that a ball thrown horizontally over level ground will
strike the ground at the same time, no matter how hard it is
thrown.

(f) If no prunes are atherogenous, but some bivalves are
atherogenous, can you conclude that some prunes are not
bivalves?

(g) Deduce, as impersonally as possible, the opinion of you
held by some other person.

REFERENCES

William James, _Principles of Psychology_, 1890, Vol. II, pp. 325-371.
John Dewey, _How We Think_, 1910.

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CHAPTER XIX

IMAGINATION

MENTAL AS DISTINGUISHED FROM MOTOR MANIPULATION

From discovery we now turn to invention, from exploration to manipulation.

The human enterprise of exploration, which we have examined under the
headings of perception and reasoning, as well as earlier under
attention, runs the gamut from simple exploratory movements of the
sense organs in looking and listening, to the elaborat