In 1830 Robert Macnish wrote the preface to the first British edition of his book ‘The Philosophy of Sleep’ (the first American edition, which was actually the 2nd British edition was published in 1834, here, a final 3rd edition was published in 1836 and soon after this Dr. Macnish died at the age of 35). The book was intended to “to supply what had hitherto been a desideratum in English literature, viz. a complete account of Sleep”. What ‘The Philosophy of Sleep’ and the other 19th Century sleep books reminds us is that whilst we have indeed made many major advances concerning the ‘science’ of sleep, our basic practical understanding of the importance of sleep and our advice to the public has not much changed over the last 200 years, (just look at any of the myriad of sleep self-help books available). Macnish was also a well-regarded writer and poet and one of the great pleasures of his book is the beauty of the language. Below I give a few select quotes; which I will leave it to the reader to think how a modern day sleep expert, could say them better-•“it (sleep) has a natural tendency to recur every twenty four hours and the periods of its accession coincide with the return of night”•“The profoundness of sleep differs also during the same night. For the first four or five hours, the slumber is much heavier then towards morning. The cause of such difference is obvious, for we go to bed exhausted by previous fatigue, and consequently enjoy sound repose, but in the course of a few hours, the necessity for this gradually abates, and sleep becomes much lighter. From this circumstance, dreams are much more apt to occur in the morning than in the early part of the night”•“Sleep, which shuns the light, embraces darkness, and they lie down together most lovingly under the spectre of midnight”•“Sleep exists in two states- in the complete and incomplete” but where sleep is incomplete “as in dreaming, only certain of the mental functions are arrested, while others continue to act as usual”•“There are two types of complete sleep-the light and the profound. So far as the extinction of the usual faculties goes, they are equally perfect, but the first is more easily broken then the other…”•“The cure of almost any disease is favoured by sleep”•“The strength given to the mind by slumber, is not less remarkable than that which it inspires in the body”•“As a general rule, the person who eats nothing for two or three hours before going to rest, will sleep better then he who does”•“Too little and too much sleep are equally injurious”•“At what ever period we go to sleep, one thing is certain, we can never with impunity convert day into night”.