Let us, for the sake of argument, suppose that some sane persons are capable of hallucinatory impressions akin to but less transient than illusions hypnagogiques, when, as far as they or others can perceive, they are wide awake. Of such sane persons Goethe and Herschel were examples. In this way we can most easily envisage, or make thinkable by ourselves, the nature of the experiences of Jeanne d’Arc and other seers. In the other state of semi-somnolence, while still alert enough to watch and reason on the phenomena, we occasionally, though less commonly, hear what may be called ‘inner voices.’ That is to say, we do not suppose that any one from without is speaking to us, but we hear, as it were, a voice within us making some remark, usually disjointed enough, and not suggested by any traceable train of thought of which we are conscious at the time. This experience partly enables us to understand the cases of sane persons who, when to all appearance wide awake, occasionally hear voices which appear to be objective and caused by actual vibrations of the atmosphere. I am acquainted with at least four persons, all of them healthy, and normal enough, who have had such experiences. In all four cases, the apparent voice (though the listeners have no superstitious belief on the subject) has communicated intelligence which proved to be correct. But in only one instance, I think, was the information thus communicated beyond the reach of conjecture, based perhaps on some observation unconsciously made or so little attended to when made that it could not be recalled by the ordinary memory. We are to suppose, then, that in such cases the person concerned being to all appearance fully awake, his or her mind has presented a thought, not as a thought, but in the shape of words that seemed to be externally audible. One hearer, in fact, at the moment wondered that the apparent speaker indicated by the voice and words should be shouting so loud in an hotel. The apparent speaker was actually not in the hotel, but at a considerable distance, well out of earshot, and, though in a nervous crisis, was not shouting at all. We know that, between sleeping and waking, our minds can present to us a thought in the apparent form of articulate words, internally audible. The hearers, when fully awake, of words that seem to be externally audible, probably do but carry the semi-vigilant experience to a higher degree, as do the beholders of visual hallucinations, when wide awake. In this way, at least, we can most nearly attain to understanding their experiences. To a relatively small proportion of people, in wakeful existence, experiences occur with distinctness, which to a large proportion of persons occur but indistinctly, ‘On the margin grey ‘Twixt the soul’s night and day.’