staking collection of facts, their
explanation through the single encompassing formula of evolution
occurs, or when to the mind of Newton the hypothesis
of gravitation suddenly suggests itself.

The encouragement of a lively play of the mind over experience,
the stimulation of imagination or what Bertrand Russell
calls "the joy of mental adventure" is thus one of the
most important sources of art and science. The arousing of
imagination depends primarily on the inherited curiosity of
man which varies from the random and restless exploring
of the child to the careful and persistent investigation of the
trained scientist. The curiosity which prompts the child to
experiment with objects in a hit-or-miss fashion is little more
than the physiological overflow of action which has been noted
above.

Curiosity becomes more distinctively mental when it is
social in character, when the child explores and experiments
not by its own manipulations but by communication, by asking
questions of other people.

When the child learns that he can appeal to others to eke out his
store of experiences, so that, if objects fail to respond interestingly to
his experiments, he may call upon persons to provide interesting material,
a new epoch sets in. "What is that?" "Why?" become the
unfailing signs of a child's presence. At first this questioning is
hardly more than a projection into social relations of the physical
overflow which earlier kept the child pushing and pulling, opening
and shutting. He asks in succession what holds up the house, what
holds up the soil that holds the house, what holds up the earth that
holds the soil; but his questions are not evidence of any genuine
consciousness of rational connections. His _why_ is not a demand
for scientific explanation; the motive behind it is simply eagerness
for a larger acquaintance with the mysterious world in which he is
placed. The search is not for a law or principle, but only for a bigger
fact.... But in the feeling, however dim, that the facts which
directly meet the sense are not the whole story, that there is more
behind them and more to come from them, lies the germ of
_intellectual_ curiosity.[1]

[Footnote 1: Dewey: _loc. cit._, p. 32.]

Curiosity passes thus from casual rudimentary inquiry
into genuinely scientific investigation. At first it is merely
physical manipulation, then merely disconnected questionings;
it becomes genuinely intellectual when it passes from
"in