The Ascent of Man: Chapters 7 - 8. Isaac Newton is born in 1642 to a widowed mother. As Galileo had predicted, the center of commerce in Europe was moving north, away from the Mediterranean, due to contact and trade with the Americas. After Newton's graduation from Cambridge, the Plague struck in 1665 and '66 - and in those years he did his most important work. First he proved that white light is diffracted into colors by the prism, then he began work on his theory of gravitation. But that work did not see the light of day until 1684 in the course of a debate with Christopher Wren; its final fruit was the Principia Mathematica in 1687. Newton's assumptions about space and time held until the beginning of the 20th century, when Einstein came on the scene. Meanwhile, the 18th and 19th Centuries saw the birth of the Industrial Revolution, when men like Brindley and Telford built Britain's infrastructure. The American Franklin did important work in electricity, and in France, Carnot laid the foundations of thermodynamics; most importantly, the unitary nature of energy came to be understood. Citing the Romantic poets, Bronowski discerns in the age "the sight of nature as a new quickening of the spirit because the unity in it was immediate to the heart and mind." The unity and diversity of the natural world will be the theme of the next section.
Peterson: Rules 7 and 8. "Pursue what is meaningful, not what is expedient" entails, first, the delay of gratification. JBP hypothesizes the evolution of saving and sharing behavior amongst mammoth-eating prehistoric humans. From there, he explores the conception of sacrifice in religion. He also touches on the evil of conscious, calculated cruelty - a recurring theme in the book. ("You understand what pain means. And once you truly understand such feelings in yourself, how they're produced, you understand how to produce them in others." - p. 175) He develops the idea that ideas within us have personalities of their own (p. 195 - another key theme of the book). "What is meaningful," he concludes, "is the organization of what would otherwise be merely expedient into a symphony of Being." Meaning depends on truthfulness, the theme of Rule 8: "Tell the truth, or at least don't lie."