Clairvoyance is the ability to see into the future. This ability is hotly disputed by skeptics, but this is an ancient art, dating back thousands of years. The first recorded instances of clairvoyance were actual rituals, including 'reading the entrails' of sacrificed animals to foretell the future, including the outcome of battles. These were also called 'auspices' in many cases, even in disparate cultures like ancient Greece and China.
The first systematic form of popularized clairvoyance was the I Ching, a formalized method of reading and interpreting the forces which affect individuals. These methods were based on the concept that using randomizers like throwing coins, bones, or sticks of herbs reflected the forces affecting the individual, if they could be interpreted properly.
The original I Ching used only basic line symbols, but was later expanded to include a double set of these factors. The combinations of lines represent specific forces, which are interpreted in terms of their order of occurrence and the meaning of their combinations. The I Ching remains popular to this day, and even survived the book burning vandalism of the First Emperor, Shih Huang Ti.
Other forms of clairvoyance include the European seers, whose ability to see future events was considered mystic. This group is in fact typical of all human societies since prehistory, and some consider the ability to predict events to be no more than a natural capacity in some individuals.
The classic example of the most famous clairvoyant is Nostradamus, a European writer who predicted the rise of Napoleon and Hitler hundreds of years before the events. Clairvoyance, like most other human abilities involving any form of unexplained mental capacity, was generally considered witchcraft or some other form of subversive behavior by religions and conservative groups.