A Quote by E. Parmalee Prentice on dependence, earth, facts, history, inclusion, labor, progress, time, and understanding

If anyone wants to understand the course of man on earth, he must consider the fact of the long pause, three million years on the level of savagery, ten thousand years on the level of dependence on the fruits of hand labor, and a hundred or a hundred and fifty years of sudden sharp rise. One hundred or 150 years is the time included in what we call progress in man's history.