Aristotle on sleep and dreams 187
Before considering the difficulties that arise here, let us first consider
Aristotle’s methodology in this short work. Basically, Aristotle tackles the
mysterious phenomenon in three ways:
(i) by considering the causal relation between the dream in which a certain
event is foreseen, and the event that later actually happens
(ii) by considering the kinds of events that can be foreseen in sleep
(iii) by considering the kinds of people who have prophetic dreams.
He does not explicitly present these research questions at the beginning
of the treatise itself in the way he does inOn Sleep andOn Dreams,
although questions (i) and (ii) are included in the summary of questions
at the beginning ofOn Sleep and Waking, where he says that he is going to
consider
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[We also need to examine] whether it is possible to foresee the future in sleep
or not, and if it is possible, in what way; and whether [it is possible to foresee]
only what will be done by human beings, or also things whose cause belongs to
the domain of what is beyond human control (to daimonion)^28 and which occur
naturally or spontaneously.
In his discussion of these issues, he once again makes a number of
empirical claims:
1. Some people foresee what will happen at the Pillars of Heracles or at the
Borysthenes ( 462 b 24 – 6 ).
2. When one is asleep, weak impulses appear stronger: weak sounds are perceived
as thunder, a tiny bit of phlegm is perceived as honey, local warmth brings
about the illusion that one goes through a fire; only after awakening, one
recognises the real nature of these impulses ( 463 a 11 – 18 ).
3. In sleep one often dreams of things one has experienced in the waking state
( 463 a 22 – 4 ).
4. One often thinks of a person who shortly later appears ( 463 b 1 – 4 ).
5. Not only man, but also some other animals dream ( 463 b 12 ;cf.Hist. an. 536
b 27 ff. and 537 b 13 ).
6. Garrulous people and melancholics often have clear and prophetic dreams ( 463
b 17 – 22 ).
7. Many dreams do not come true ( 463 b 22 ).
8. Foresight of things happening beyond the dreamer’s control does not occur
with intelligent people, but with those of mediocre mental capacities ( 463 a
19 – 20 ).(^28) For a discussion of this expression see van der Eijk ( 1994 ) 291 – 6.