Observation and reflection show us that the mind originates nothing during sleep; it merely remembers--and often in the most chaotic manner--the thoughts, the fancies, the impressions which have been imagined or received by the individual when awake. Sometimes ideas are reproduced in dreams exactly as they have occurred to us in our waking moments, and this may take place night after night with scarcely the alteration of a single circumstance. A friend informs me that he is very subject to dreams of this character, and that on some occasions the repetition has taken place as many as a dozen times. A very striking instance of this kind occurred to me a few years since, and made a deep impression on my mind. I had just read Schiller’s ode to Laura, as translated by Sir E. Bulwer Lytton, beginning, “Who and what gave to me the wish to woo thee?” and admired it as a striking piece of versification conveying some noted philosophical ideas in a forcible and beautiful manner. The following night I had a very vivid dream of a condition of pre-existence, in which I imagined myself to be. The connection between the dream and the poem I had been reading was sufficiently well marked, and did not astonish me. I was, however, surprised to find that the next night I had exactly the same dream, and that it was repeated three times subsequently on consecutive nights. The dependence of dreams upon ideas which we have had when awake was well known to the ancients. Thus Lucius Accius,[77] a poet who lived more than a hundred and fifty years before the Christian era, says: “Quae in vita usurpant homines, cogitant, curant, vident Quaeque agunt vigilantes, agitantque casi cui in somno accidant, * * * * * * Minus mirum est.” Lucretius[78] declares that during sleep we are amused with things which have made us weep when awake; that circumstances which have pleased us are recalled to our minds; that objects are presented to us which occupied our thoughts long before; and that recent events appear still more vividly before us. Petronius Arbiter[79] cites Epicurus to the same effect. Tryphæna having declared that she had had a dream in which there appeared to her the image of Neptune she had seen at Baiæ, “Hence you may perceive,” observed Eumolpus, “what a divine man is Epicurus, who so ingeniously ridiculed these sports of fancy.