Os Guinness traces our contemporary idea of human freedom that "began in the Renaissance … blossomed in the Enlightenment and rose to its climax in the 1960s." The classic statement of the Renaissance view is that of Pico della Mirandola, as he imagines God addressing Adam: "You, who are confined by no limits, shall determine for yourself your own nature …. You shall fashion yourself in whatever form you prefer."

Throughout the centuries this same view of human freedom—limitless potential apart from God—has been expressed by other key thinkers.

• Leon Batista Alberti: "A man can do all things if he will." (15th century, Italy)
• Karl Marx: "Man is free only if he owes his existence to himself." (19th century, Germany)
• Friedrich Nietzsche: "If there were gods, who could bear not to be gods? Therefore there are no gods." (19th century, Germany)
• Herbert Spencer: "Progress is not an accident, but a necessity. Surely must evil and immorality disappear; surely must men become perfect." (19th century, England)
• Walt Whitman: "One's-self I sing, a simple separate person." (19th century, America)
• John F. Kennedy: "Man can be as big as he wants. No problem of human destiny is beyond human beings." (20th century, America)
• Ayn Rand: "Man's destiny is to be a self-made soul." (20th century, Russian-American)
• E.O. Wilson: "Humanity will be positioned godlike to take control of its own ultimate fate." (21st century, America)