Over the ages, scholars have described conscious or lucid dreaming in different ways, attributing various elements to the state such as self-awareness, control over dream content, emergence of shamanic consciousness, and even feeling like a God in a private universe.
Aristotle, 4th century BCE, Treatise on dreams
“If the sleeper perceives he is asleep, and is conscious of the sleeping state during which the perception comes before his mind, it presents itself still, but something within him speaks to this effect: “The image of Koriskos presents itself, but the real Koriskos is not present.””
St. Thomas Aquinas, 15th century, Letters
“not only does the imagination retain its freedom, but also the common sense is partially freed; so that sometimes while asleep a man may judge that what he sees is a dream, discerning as it were, between things and their images”
Sigmund Freud, 1909, Interpretation of Dreams, introduction to 2nd edition
“There are some people who are quite clearly aware during the night that they are asleep and dreaming and who thus seem to possess the faculty of consciously directing their dreams.”
Frederick van Eeden, 1913, A study of dreams
A “lucid dream” is when “The sleeper remembers day-life and his own condition, reaches a state of perfect awareness, and is able to direct his attention and to attempt different acts of free volition” (van Eeden, 1913).
Friedrich Nietszche, 1870, Birth of a tragedy
“And perhaps many a one, like myself, recollect having sometimes called out cheeringly and not without success amid the dangers and terrors of dream life: “It is a dream! I will dream on!””
Oliver Fox, 1930s
“Dreams of knowledge” occur when “Secure in the consciousness of my true condition and the knowledge that I could always wake if danger threatened, moving like a little God through the glorious scenery of the dream world.” (as quoted in LaBerge, 1988, p. 20).
Paul Tholey, 1981
Lucid dreaming must include “full awareness of the dream state, awareness of the possibility of making free decisions, clear consciousness of the dreamer, perception by all senses, full memory of waking life, full memory of all lucid dream experiences in the waking state and in the lucid dream state, awareness of the meaning of symbols.”
Charles Tart, 1991, Lucidity
“Lucid dreaming is an altered d-SoC (discrete state of consciousness) characterized by the lucid dreamer experiencing himself as located in a world or environment that he intellectually knows in “unreal” (or certainly not ordinary physical reality) while simulataneously experiencing the overall quality of his consciousness as having clarity, the lucidity of his ordinary waking d-SoC.”
Jayne Gackenbach, 1991, Lucidity
“A dream during which one knows one is dreaming while the dream is ongoing.”
Celia Green and C. McCreery, 1994, Lucid Dreaming
“We think it is important to restrict the definition of a lucid dream entirely to the presence or absence of this one factor, the dreamer’s awareness of his state.”
Michael Winkleman, 2000, Shamanism
Lucid dreaming exemplifies “shamanic consciousness” as it “integrates the potentials of dreaming and waking consciousness.”
Stephen LaBerge, 2005, Dreaming 16(2)
“Lucid dreaming refers to a specific dream state characterized by the dreamer’s awareness of being in a dream and the ability to volitionally control its content.”
You may also be interested in my article about the history of lucid dreaming.