arge measure on what we are; and that what we are
rests back on what we have been. In anything we try to think or feel or
do, we quickly reach a limit; and this limit is determined by the
original quality of our nervous system plus the training it has
received. For here is the curious fact about this instrument of thought
and feeling which at once takes it away from comparison with mechanical
instruments. Whatever it does, becomes a part of itself, and then helps
to determine what it will do the next time and how it will do it. With
the making easy of mental operations through repetition, and with the
formation of associations based on our choices, it may be truly said
that we become whatever we habitually think and feel and do.

Every choice we make is thus literally built into our character and
becomes a part of ourselves. After that, the old choice will help
determine the new, and we shall find ourselves being directed by all of
our past choices, and even by the choices of our ancestors. Since, then,
all our earlier selves are continued in us and make us what we are, we
are simply studying ourselves when we study the history of our
ancestors. If we would go forward, we must first look backward; for we
must rise on stepping-stones of our dead selves.

But history is not merely the story of the past. To relate that, would
take as long as it took to live it, and the result would be but
weariness of spirit. History, to be significant, must select the events
with which it will deal; it must arrange these in series that are in
accord with the constitution of things; and then it must use the
generalizations it reaches to interpret the present, and even to
forecast the future. It is obvious that this interpretation will depend
on the point of view held by the interpreter.

Hence we must ask in what fundamental beliefs this presentation rests.
These are, first, that life tends to move along certain lines that
constitute the law of human nature. Just as the infant tends first to
wriggle, then creep, then walk, then run and dance, so human nature
tends to move upward from savagery through primitive settled life to the
complex forms of larger settled units. In this progress, material or
economic forces play a large part; but ideas, originally born out of
circumstances, but sometimes borrowed from other people, sometimes
degenerate remnants of past utilities, also play a large part. The
progress we finally make is thus directed