Dreams of flying, with the dreams of falling they are sometimes associated with, may fairly be considered the best known and most frequent type of dream. They were among the earliest dreams to attract attention. Ruths argues that the Greek conception of the flying Hermes, the god who possessed special authority over dreams, was based on such experiences. Lucretius, in his interesting passage on the psychology of dreaming, speaks of falling from heights in dreams;[100] Cicero appears to refer to dreams of flying; St. Jerome mentions that he was subject to them; Synesius remarked that in dreams we fly with wings and view the world from afar; Cervantes accurately described the dream of falling.[101] From the inventors of the legend of Icarus onwards, men have firmly cherished the belief that under some circumstances they could fly, and we may well suppose that that belief partly owes its conviction, and the resolve to make it practical, to the experiences that have been gained in dreams. No dreams, indeed, are so vivid and so convincing as dreams of flying; none leave behind them so strong a sense of the reality of the experience. Raffaelli, the eminent French painter, who is subject to the dreaming experience of floating in the air, confesses that it is so convincing that he has jumped out of bed on awaking and attempted to repeat it. 'I need not tell you,' he adds, 'that I have never been able to succeed.'[102] Herbert Spencer mentions that in a company of a dozen persons, three testified that in early life they had had such vivid dreams of flying downstairs, and were so strongly impressed by the reality of the experience, that they actually made the attempt, one of them suffering in consequence from an injured ankle.[103] The case is recorded of an old French lady who always maintained that on one occasion she actually had succeeded for a few instants in supporting herself on the air.[104] No one who is familiar with these dreaming experiences will be inclined to laugh at that old lady. It was during one of these dreams of levitation, in which one finds oneself leaping into the air and able to stay there, that it occurred to me that I would write a paper on the subject, for I thought in my dream that this power I found myself possessed of was probably much more widespread than was commonly supposed, and that in any case it ought to be generally known.