Okay, I'll weigh in with the invention of secularism — getting out from under the thumbs of the gods.
From all we can tell from historians and anthropologists, every ancient society worshipped some god or other. Superstition ran rampant. Human beings denied their own freedom and autonomy by praising or blaming the gods for their fates. Not until some bold minds like Ludwig Feuerbach, Karl Marx, Friedrich Nietzsche and Sigmund Freud did it become thinkable, much less fashionable, to preach atheism. These were inventors of a new order, one that allowed human beings to make up our game as we go along, unfettered by superstitions about the will of the gods or fear of their punishment.
For my part I am appalled at how slowly this invention has been accepted. Over 60 percent of Americans still agree (somewhat, mostly, or strongly) that, "The world was literally created in six days, as the Bible says," (confirmed on three successive national probability sample surveys by the Values and Lifestyles Program at SRI International where I was director of research during the 1980s). Islam claims over a billion devotees. And I find it remarkable the number of highly educated, intelligent adults who still embrace a childlike, wish-fulfilling belief in God.
Without kneeling down to positivism, or overestimating what is knowable, or underestimating the mysteries that remain lurking in the individual and social unconscious, let us nevertheless celebrate our liberation from superstition, remain humble before forces that transcend our individual egos, but accept the collective responsibilities of human freedom, and sing, as my GBN partner, Stewart Brand, did in the epigram for the Whole Earth Catalog: "We are as gods so we might as well get good at it."