Robert Macnish, The Philosophy of Sleep ( Glasgow: W. R. M'Phun, 1830), 50-3, 117-18, 124-8, 136-9, 143.
This short study of the physical and mental processes at work in sleeping and dreaming became a standard reference in the nineteenth century, and is, indeed, cited by Freud in his discussion of "The Stimulii and Source of Dreams" in The Interpretation of Dreams (The Standard Edition of the Complete Works of Sigmund Freud, trans. James Strachey, vol. iv ( 1900), 24). Like other popular scientific treatises, it draws on a wide range of theories and interpretations and brings together numerous case-studies, while reflecting Macnish's own strong phrenological interests.
A suspension (almost always complete) of the judgment, and an active state of memory, imagination, &c., are the only conditions essential to ordinary dreaming; but along with them there is usually a torpor of the organs of the senses, and of the powers of voluntary motion, the same as in complete sleep. Dreaming, therefore, is a state of partial slumber, in which certain parts of the brain are asleep, or deprived of their sensorial power, while others continue awake, or possess their accustomed proportion; and whatever produces dreams has the effect of exhausting this power in one set of faculties, while it leaves it untouched in others. Dreaming, then, takes place when the repose is broken; and consists of a series of thoughts or feelings called into existence by certain powers of the mind, while the other mental powers which control these thoughts or feelings, are inactive. This theory is the only one capable of affording a satisfactory explanation of all the phenomena of dreams. It embraces every difficult point, and is so accordant with nature, that there is every reason to suppose it founded on truth. [...]
In dreaming, the voluntary powers are generally, but not necessarily sus-