Will and Ariel Durant write in The Lessons of History (1968,)

If we put the problem further back, and ask what determines whether a challenge will or will not be met, the answer is that this depends upon the presence or absence of initiative and of creative individuals with clarity of mind and energy of will (which is almost a definition of genius,) capable of effective responses to new situations (which is almost a definition of intelligence.) If we ask what makes a creative individual, we are thrown back from history to psychology and biology—to the influence of environment and the gamble and secret of the chromosomes.