What are the motifs in The Story of Mankind by Hendrik Willem Van Loon?

Technological advancement has dominated the course of history since man first invented tools. With each step, man has served to increase his presence on the earth and to improve his own quality of life, while often simultaneously causing drastic negative consequences to the planet or to other populations. In the beginning, it was technological advancement that made mankind able to survive while other species did not. The wheel, the hammer, the spear, and other primal tools helped man to evolve into a thinking, reasoning creature. His learning of writing and language allowed him to share knowledge with other individuals. By the time of the Romans and the Greeks, technology has advanced to allow soldiers better weapons and better armor, and allow doctors to improve health conditions and food growth potential.