On Sleep And Sleeplessness   

1



WITH regard to sleep and waking, we must consider what they are:

whether they are peculiar to soul or to body, or common to both; and

if common, to what part of soul or body they appertain: further,

from what cause it arises that they are attributes of animals, and

whether all animals share in them both, or some partake of the one

only, others of the other only, or some partake of neither and some of

both.

Further, in addition to these questions, we must also inquire what

the dream is, and from what cause sleepers sometimes dream, and

sometimes do not; or whether the truth is that sleepers always dream

but do not always remember (their dream); and if this occurs, what its

explanation is.

Again, [we must inquire] whether it is possible or not to foresee

the future (in dreams), and if it be possible, in what manner;

further, whether, supposing it possible, it extends only to things

to be accomplished by the agency of Man, or to those also of which the

cause lies in supra-human agency, and which result from the workings

of Nature, or of Spontaneity.

First, then, this much is clear, that waking and sleep appertain

to the same part of an animal, inasmuch as they are opposites, and

sleep is evidently a privation of waking. For contraries, in natural

as well as in all other matters, are seen always to present themselves

in the same subject, and to be affections of the same: examples

are-health and sickness, beauty and ugliness, strength and weakness,

sight and blindness, hearing and deafness. This is also clear from the

following considerations. The criterion by which we know the waking

person to be awake is identical with that by which we know the sleeper

to be asleep; for we assume that one who is exercising

sense-perception is awake, and that every one who is awake perceives