The concept of a universal, linear time did not appear right away. In the ancient Hindu tradition, for instance, time had essentially no boundaries, and, like the ancient symbol of the ouroboros—the snake biting its own tail—the universe was assumed to undergo continuous cycles of destruction and regeneration. Nevertheless, the Hindu sages of antiquity did come up with a rather “precise” number for the Earth’s age, which in 2013 was supposed to be 1,972,949,114 years. In the Western tradition, Plato and Aristotle were much more concerned with why and how the existing order of nature came about than with when, but even they toyed with the idea of recurring cycles, in step with the heavenly motions. In the Christian world, on the other hand, a circular time was rejected in favor of a unique, nonrepeating straight line, leading from creation to the Last Judgment. In this religious context, determinations of the age of the Earth had been for centuries the exclusive province of theologians. In one of the earliest estimates, Theophilus, the sixth bishop of Antioch, concluded in the year 169 that the world had been created some 5,698 years earlier. His motivation for calculating the age, he declared, was not “to furnish mere matter of much talk” but “to throw light upon the number of years from the foundation of the world.” While Theophilus did allow for a certain margin of error in his calculation, he did not think the error would exceed 200 years.

Many of the chronologists that followed him tended to simply add up time intervals between key biblical events, the scriptural ages at death of certain individuals, or the span of generations. Prominent among these biblical scholars were John Lightfoot, the seventeenth-century vice chancellor of Cambridge University, and James Ussher, who became archbishop of Armagh in 1625. Even though the title of Lightfoot’s 1642 short book was carefully constructed to read A Few, and New Observations, upon the Book of Genesis: The Most of Them Certain, the Rest Probable, All Harmless, Strange, and Rarely Heard of Before, Lightfoot did not hesitate to pronounce that the creation of the first human—Adam—occurred precisely at nine o’clock in the morning! As for the date of the creation of the world, Lightfoot settled on 3928 BCE.

Ussher’s calculation was somewhat more sophisticated in that he complemented the biblical accounts by some astronomical and historical data. His punctilious conclusion: The world appeared on the evening before October 23, in the year 4004 BCE. This particular date became well known in the English-speaking world, since it was added as a marginal note to the English Bible in 1701.

Naturally, the Christian view of time followed largely upon the heels of the Jewish tradition, which was also based mostly on a literal reading of the narrative in the book of Genesis. In the context of a divine drama in which the Jewish people were supposed to play the principal role, having a history was clearly crucial. According to this heritage, the world was created some 5,773 years ago (as of 2013). Prophetically, one of the most influential Jewish scholars of the Middle Ages—Maimonides (Moshe ben Maimon)—advocated against a literal interpretation of the biblical text. As if anticipating what Galileo Galilei would say more than four centuries later, Maimonides argued that whenever accurate scientific findings are in conflict with the Scriptures, the biblical texts should be reinterpreted. The Dutch Jewish philosopher Baruch de Spinoza echoed the same sentiments: “The knowledge of . . . nearly everything contained in Scripture, must be sought only from Scripture itself, just as the knowledge of nature is sought from nature itself.” In fact, Maimonides was not even the first to suggest that the passages in Genesis had been intended only allegorically. In the first century, the Hellenistic Jewish philosopher Philo Judaeus of Alexandria wrote presciently:

It would be a mark of great naïvety to think that the world was created either in six days, or indeed in time at all; for time is nothing but the sequence of days and nights, and these things are necessarily connected with the motion of the Sun above and below the Earth. But the Sun is a part of the heavens, so that time must be recognized as something posterior to the world. So it would be correct to say not that the world was created in time, but that time owed its existence to the world.