I honor health as the first muse, and sleep as the condition of health. Sleep benefits mainly by the sound health it produces; incidentally also by dreams, into whose farrago a divine lesson is sometimes slipped. – Ralph Waldo Emerson, Letters and Social Aims, “Inspiration”

[B]y far the larger number of the dreams… occurred towards dawn; sometimes even, after sunrise, during a “second sleep.” A condition of fasting, united, possibly, with some subtle magnetic or other atmospheric state, seems therefore to be that most open to impressions of the kind. – Dr. Anna Bonus Kingsford, 1886, preface to Dreams and Dream-Stories, 1888