Curiosity goes back to the dawn of human existence (EXIST). This irrepressible desire to know is not a (CHARACTER) of inanimate objects. Nor does it seem to be attributable to some forms of living organism which, for that very reason, we can scarcely bring ourselves to consider alive. A tree, for example, does not display (RECOGNISE) curiosity, nor does a sponge or even an oyster. If chance events bring them poison, predators or parasites, they die as (CEREMONIOUS) as they lived.

Early in the scheme of life, (DEPEND) motion was developed by some organisms. It meant an (ORDINARY) advance in their control of the environment. A moving organism no longer waited in stolid (RIGID) for food to come its way, but went out after it. The individual that hesitated in the (ZEAL) search for food, or that was overly (CONSERVE) in its investigation, starved.

As organisms grew more complex, more messages of greater variety were received from and about the (ROUND) environment. At the same time, the nervous system, the living instrument that interprets and stores the data collected by the sense organs, became (INCREASE) complex.