Medicine and philosophy - Classical Homeopathy Online

182 Aristotle and his schoolrefers explicitly in 463 a 4–5), and perhaps also from literary descriptionsof dreams such as were found in Homer and the epic tradition. However,since this tradition has only been preserved in fragments, it is difficult toassess the extent of his dependence on earlier sources.Yet when looking more closely at the way in which these empirical‘data’ are used in Aristotle’s argument in On Dreams, it becomes clear thatthe treatise goes far beyond the level of empirical fact-finding. Aristotledoes not present his theory as being built up, so to speak, inductively onthe basis of a number of observations; on the contrary, the three researchquestions mentioned above ((i), (ii) and (iii)) are treated in a systematicaland deductive way, and empirical ‘data’ are mentioned in the course of thistheoretical argument – often in the form of examples or analogies – inorder to support or clarify opinions and presuppositions which Aristotlealready seems to take for granted. And although Aristotle’s style of reasoningseems very cautious and essayistic – the first chapter, for example, is highlyaporetic 25 – it is, in fact, rather dogmatic. The general impression one gets isthat empirical evidence is primarily mentioned when it suits the argument –and if not, it is either ignored or explained away in a questionable manner.Thus at the end of On Dreams, it turns out that the three questions raisedat the beginning are to be answered as follows:(i) Dreams belong to the sensitive part of the soul qua imaginative part(459 a 21); dreaming is not an operation of sense-perception but of ‘imagination’,which is defined by Aristotle as ‘the movement which occurs asa result of actual perception’ (459 a 17–18). This definition, together withAristotle’s use of the words phantasia, phantasma, and phainesthai, isinbroad agreement with his general theory of ‘imagination’ in On the Soul,to which he explicitly refers (459 a 15). In the course of the long argumentwhich leads to this conclusion, only claims (1) and (2) play a part; for therest, the argument is purely theoretical and logical.(ii) How do dreams come into being? Aristotle assumes the followingmechanism: During the waking state, the sense-organs are stimulated bya great quantity of sense-movements (stimuli brought about by sensibleobjects); but not all of these movements are equally strong. The strongermovements overrule the weaker, so that the weaker are ‘not noticed’ by theperceiving subject (460 b 28–461 a 8). Aristotle assumes, however, that theremnants of these weaker movements remain present in the sense-organsin the form of traces. When in sleep the sense-organs have stopped beingactive – and as a result of this cannot receive new stimuli – the remnants of25 For an analysis see van der Eijk (1994) 36–8.