 Humans in the late 21st century, along with the other races of the Galactic Milieu (the Lylmik, Gi, Krondaku, Poltroyans, and Simbiari) and the Tanu and Firvulag of the Pliocene epoch, have developed psychic powers.The psychic powers of Julian May's books are seemingly magical powers which go far beyond the 'simple' psychic abilities we more commonly think of, such as clairvoyance, telepathy, and telekinesis.The human race is a blend of 'operant' metapsychics (not very many, but more born every day), 'latent' metapsychics (uncommon, and unable to use their potential abilities for a number of reasons, but their offspring have a higher chance to be brought to operancy when born), and those with no useful metapsychic potential at all (most of humanity).