Introduction In the first days of the men’s consciousness, all phenomena (man’s creation, rainbows, Sun, comets, winds, floods, Earth’s place in the cosmos, planets, lightning, earthquakes, diseases,) were ascribed to some god or invisible spirit by lamas, seers, oracles, shamans, sorcerers, divines, holy men, rabbis, gurus (all called here “priests”) who claimed some connection with the gods or invisible spirits. Priests’ explanations comforted the common people. Priests thus had power over the common people. Priests told the people what the gods wanted. Throughout history, belief in supernatural entities, has been the norm. Few questioned it. But the gods/ spirits were unpredictable, or their explanations were unclear. So a few persons, beginning in the sixth century BC tried to find better explanations of events, known as “The Quest for Certainty.” This quest for better explanations was opposed, often by violence, by priests, who realized, correctly, that their personal power and authority would diminish if non-priestly explanations worked. Pope Gregory the Great in AD 591 admitted, “Faith hath no merit where human reason supplies proof.” Can one consider himself educated if he does not appreciate the remarkable persons who got us where we are today. Persons like Thales, Socrates, Plato, Aristotle, Aquinas, Augustine, Descartes, da Vinci, Newton, Voltaire, Kant, Galileo, Luther, Madame Curie, Erasmus, Darwin, Einstein, Spinoza, Marx, Hume, Jefferson, Lincoln, and Machiavelli? All these and many more great thinkers are described in plain language as they have arisen in history.
An Incomplete History of Knowledge The Struggle against the Priests Thomson von Stein  The Homo sapiens savage in Africa 100,000 years ago with an average lifespan of 20 years and foraging for food armed with a sharpened stick was fully as intelligent as the PhD scientist of today. Their brains and neo-cortices are identical. What is the difference between them? Knowledge. This history describes the most important advances in knowledge that got us from there to here.

All knowledge resolves itself into probabilities...Every statement is either 1. True or false by definition (whose denial is false), or 2. Contingent unnecessary assertions, those dependent on empirical proof (whose negations are not necessarily false), or 3. Nonsense.  -David Hume