188 Aristotle and his school
9. Foresight is characteristic of people who are prone to anger or to melancholics
( 464 a 24 – 7 ; 464 a 32 –b 5 ).
10. Prophetic dreams mostly concern people who are related to the dreamer ( 464
a 27 – 32 ).
11. Images in moving water are often distorted and difficult to reconstruct ( 464
b 10 – 12 ).
In his treatment of question (i), Aristotle in turn distinguishes three possi-
bilities:
(a) The dream may be a sign (s ̄emeion) of the event, in that it is caused
by the same factor or starting-point which also causes the future event
itself. In order to illustrate this possibility, he refers to the prognostic
use of dreams as signs in medicine, and he uses several empirical data
as evidence (no. 2 ), to which I shall turn shortly.
(b) The dream is a cause (aition), or indeedthecause, of the event, in that it
causes the event to happen. For example, it may happen that we dream
about an action which we actually perform the following day. Again,
empirical evidence of this is produced (no. 3 ): Aristotle points out that
it often happens that we dream of an action we have performed previ-
ously, and this action is the starting-point of the dream. Conversely, he
argues, we can also in our actions be motivated by a dream we have had
before.
(c) The dream coincides (sumpt ̄oma) with the event without there being
any real connection between the occurrence of both. Aristotle compares
this with the general experience many people have that we think of a
person and that a few minutes later this person suddenly turns up (cf.
no. 4 ).
In his discussion of question (ii), Aristotle makes a further, fundamental
distinction between events whose origins lie within the dreamer him/herself
and events whose origins do not lie within the dreamer. A similar distinc-
tion between human agency and things happening beyond human control
was already alluded to in the preface toOn Sleep and Wakingquoted above.
Diseases which may affect the dreamer, and actions the dreamer himself
performs, obviously belong to the category of things whose origin (arch ̄e)is
within the dreamer; but events that are ‘extravagant in time, place or mag-
nitude’ ( 464 a 1 – 4 ) such as things occurring at the ‘Pillars of Heracles’ ( 462
b 24 – 6 ) obviously belong to the latter category. Aristotle connects this dis-
tinction with the results of his earlier distinction between causes, signs and
coincidences: in cases where the origin of the event lies within the dreamer,
it can be reasonably assumed that an explanation by reference to ‘cause’ or
‘sign’ is plausible, but in the latter (the origin of the event lying outside the
