Ancient humans, lacking devices to store large amounts of information, invented and developed a system of mnemonics which evolved and passed to modern times. The mnemonics, collectively known as the Ancient Art of Memory, were discovered in 447 BC by a Greek poet, Simonides, and were adequately described by Cicero, Quintilian, and Pliny. These arts fell into neglect after Alaric sacked Rome in 410 AD, but were subsequently revived in 1323 by Saint Thomas Aquinas, who transferred them from a division of rhetoric to ethics and used them to recall Catholic doctrine and versions of biblical history. In 1540 Saint Ignatius Loyola used mnemonic images to affirm the faith with his newly formed Society of Jesus and tried to convert the Ming dynasty in China by teaching these memory skills to Chinese nobles. Today, the ancient memory arts have applications in pilot training, gambling, mentalism and telepathy demonstrations, and may have a role in the rehabilitation of brain-damaged patients. Objective testing confirms that with the use of these memory skills, recall is increased, at least 10-fold, and the memory deficits of proactive and retroactive inhibition do not exist.