Medicine and philosophy - Classical Homeopathy Online

Aristotle on melancholy 147Sleep (which makes no mention of pneuma and blood at all and whichotherwise shows a lack of physiological details too).However, close analysis of the text of On Dreams reveals a clear connectionbetween both occurrences. At the start of the third chapter Aristotleexplains what causes dreams to appear: due to their weakness, sensory movementsare obscured by stronger movements during the day; yet by night,when the individual senses are inactive, they flow to the central sensoryorgan (the ‘principle of perception’ or the ‘authoritative sense-organ’ that issituated in the heart) as a result of a flow of heat. These movements often stillresemble the object originally perceived, but equally often they take on differentshapes due to resistance (for this reason no dreams occur after a meal).Hence, just as in a liquid, if one disturbs it violently, sometimes no image appears,and sometimes it appears but is entirely distorted, so that it seems quite differentfrom what it really is, although when the movement has ceased, the reflections areclear and plain; so also in sleep, the images or residuary movements that arise fromthe sense-impressions are altogether obscured owing to the aforesaid movementwhen it is too great, and sometimes the images appear confused and monstrous,and the dreams are morbid, as is the case with the melancholic, the feverish andthe intoxicated; for all these affections, being full of air, produce much movementand confusion. In animals that have blood, as the blood becomes quiet and its purerelements separate, the persistence of the sensory stimulus derived from each of thesense organs makes the dreams healthy.The analogy thus has to be considered to apply to the whole process: thephrase ‘when the movement has ceased, the reflections are clear and plain’(17) corresponds to ‘as the blood becomes quiet and its purer elementsseparate’ in line 25. It shows that the process does not stop at the confusedimages in dreams: if the movement is preserved (), it will eventuallyreach the heart. It seems that Div. somn. 464 a 32ff. refers in particularto this ‘preservation’ of movements, for the ‘intensity’ of the melancholicsthat is emphasised there is responsible for this preservation, and the ‘othermovement’ discussed here seems to refer to the ‘resistance’ (ekkrousis) mentionedin Insomn. 461 a 11. The advantage of this interpretation is that in thelater treatise (On Divination in Sleep) Aristotle explicitly refers to the earlierone (On Dreams), using it to try to explain two facts and characteristicsof melancholics that at first sight seem difficult to square with each other.It appears that melancholics can have both vague and clear dreams; andwhich one of both affections manifests itself most strongly in a particularcase apparently depends on the person’s physiological state at the time(volume of air and heat, intensity of images), which in the case of unstablepeople like melancholics must be considered a variable factor.