Nostradamus' major work of prophecies, now referred to as "The Centuries," was published in installments over the course of several years. The work consisted of about a thousand quatrains, four-lined verses, collected in groups of a hundred. The title "The Centuries," which refers to the organizing structure of the work, not to periods of time, was apparently added after Nostradamus' time. His original title was simply "The Prophecies of Michel Nostradamus."
Nostradamus said he was able to predict the future through a combination of astrological study and divine inspiration. He had long studied the supposed relationship between the movement of heavenly bodies and earthly events, and he claimed an angelic spirit helped him understand how these forces would manifest themselves. He sought out inspiration through various forms of meditation, generally focusing in on fire or water, possibly while under the influence of mild hallucinogens, such as nutmeg. Meditating late at night, Nostradamus claimed, he would see and understand events in the near and distant future.
Each quatrain, written predominantly in French, with some Latin, Greek and Italian, foretells a particular event or era. These accounts are undeniably confusing: They are full of esoteric metaphor and anagrams; they include few dates or specific geographical references and are not arranged in chronological order.
According to the work's preface, a letter from Nostradamus to his son Cesar (a child from his second marriage), the verses were intended to be mystifying. Nostradamus said he was afraid he would be persecuted and his work would be destroyed if authorities in his time fully understood his predictions. According to him, his cryptic prophecies would be better understood by enlightened people in the future.
Many people today believe they possess such an enlightenment. They say that if one interprets the quatrains correctly, it is clear that a number of Nostradamus' predictions have already come true. In the next section, we'll find out how Nostradamus critics counter these claims.