Spirits are invisible disembodied beings who fulfill many different roles throughout The Vampire Chronicles. Spirits are not universally good or evil, though are often defined as good or evil by humans or other beings who interact with them. Spirits have limited powers to affect the physical realm, but may affect the weather, find lost objects, or spy on enemies. Humans who can communicate with, perceive, or command spirits are often known as witches. Spirits are generally characterized as childish and naive, and may become attached to or decide to torment specific humans. Many spirits have some desire to have a physical form, and may manipulate or use humans to achieve this goal.
Many spirits appear in The Vampire Chronicles and Lives of the Mayfair Witches, but the general reason for the existence of spirits and their origins is not known. In Memnoch the Devil, spirits are explained to be the souls of humans who once lived and who have escaped Sheol (Hell), some of which have forgotten that they were once human. The truth of Memnoch's account is questioned throughout the series, and in Prince Lestat and the Realms of Atlantis, Memnoch is referred to as a spirit himself. Gremt Stryker Knollys, another spirit, refers to the realm from which he came, but has no recollection of a former life.
Though spirits are not the exact same as ghosts, many spirits important in the series are revealed to have been mortal beings prior to becoming spirits, and it is possible that all spirits, as Memnoch indicated, once had a physical form. Lasher, first assumed to be a spirit, is actually the ghost of a taltos, Memnoch is hypothesized by the replimoid Kapetria to be the ghost of a replimoid she once knew, Goblin in Blackwood Farm is the ghost of a human child, and Amel is the ghost of a human being who was given replimoid enhancements by the Parents. It is also ambiguous but possible that some ghosts are actually spirits taking the form of a dead human who they were not in life, as is implied to possibly be the case with Claudia's ghost in Merrick.