ant the possibility of playing the internal game of thinking; but
perhaps the most important advance of all was the means of comparing
notes with neighbours, of corroborating individual experience by social
intercourse. With words, also, it became easier to enregister outside
himself the gains of the past. It is not without significance that the
Greek Logos, which may be translated "the word," may also be translated
Mind.

Sec. 9

Looking Backwards

When we take a survey of animal behaviour we see a long inclined plane.
The outer world provokes simple creatures to answer back; simple
creatures act experimentally on their surroundings. From the beginning
this twofold process has been going on, receiving stimuli from the
environment and acting upon the environment, and according to the
efficiency of the reactions and actions living creatures have been
sifted for millions of years. One main line of advance has been opening
new gateways of knowledge--the senses, which are far more than five in
number. The other main line of advance has been in most general terms,
experimenting or testing, probing and proving, trying one key after
another till a door is unlocked. There is progress in multiplying the
gateways of knowledge and making them more discriminating, and there is
progress in making the modes of experimenting more wide-awake, more
controlled, and more resolute. But behind both of these is the
characteristically vital power of enregistering within the organism the
lessons of the past. In the life of the individual these enregistrations
are illustrated by memories and habituations and habits; in the life of
the race they are illustrated by reflex actions and instinctive
capacities.

Body and Mind

We must not shirk the very difficult question of the relation between
the bodily and the mental side of behaviour.

(_a_) Some great thinkers have taught that the mind is a reality by
itself which plays upon the instrument of the brain and body. As the
instrument gets worn and dusty the playing is not so good as it once
was, but the player is still himself. This theory of the essential
independence of the mind is a very beautiful one, but those who like it
when applied to themselves are not always so fond of it when it is
applied to other intelligent creatures like rooks and elephants. It may
be, however, that there is a gradual emancipation of the mind which has
gone furthest in Man and is still progressing.

(_b