Medicine and philosophy - Classical Homeopathy Online

Aristotle on sleep and dreams 175That is explicitly and emphatically the context of natural science: the theoreticalstudy of nature as Aristotle conceives it. They belong to a series oftreatises which are usually called Parva naturalia. Although this title doesnot originate from Aristotle but from the Middle Ages, it rightly indicatesthat psychology means for Aristotle psycho-physiology, an analysis both ofthe formal (‘mental’) and of the material (‘physical’) aspects of what itmeans for a natural entity to be a living being. 17 At the beginning of thisseries of treatises (which Aristotle seems to have conceived as a continuingdiscussion of connected topics), Aristotle says that he will be concernedwith the most important ‘activities and experiences’ of living beings (man,animals, plants), in particular with those that are ‘common to the soul andthe body’: sense-perception, memory and recollection, sleep and waking,youth and old age, growth and decay, breathing, life and death, health anddisease. These are, Aristotle says, the most important functions living beingscan realise or experience qua living beings, and it is for the purposeof these functions that the bodily structures such as described in History ofAnimals and Parts of Animals (and in the lost work On Plants) exist. TheParva naturalia are closely linked to Aristotle’s work On the Soul, and thepsycho-physiological explanation of dreams which Aristotle expounds inOn Dreams (and which, in the enumeration listed above, is subordinatedto and included in the discussion of sleeping and waking) heavily drawsupon Aristotle’s general theory of the soul, especially his views on senseperception,‘imagination’ (phantasia), and on the so-called ‘central sensefaculty’ (kurion aisthētērion). This context of the study of nature shouldmake clear from the outset that the interest taken by Aristotle in dreams isneither epistemological nor practical, hermeneutic or therapeutic – as it is,for example, in the Hippocratic work On Regimen quoted above, of whichAristotle was aware.Against this background, the questions Aristotle is pursuing in the threeworks in question make perfect sense. Thus in the preface to On Sleep andWaking (453 b 11–24), which in a way serves as an introduction to all three ofthe treatises, he says that he is going to consider whether sleeping and wakingare ‘peculiar to the soul’ or ‘common to soul and body’, and, if common toboth, what parts of soul and body are involved; whether sleep occurs in allliving beings or only in some; and through what cause (aitia) it occurs. 18Considering this psycho-physiological context, one would expect Aristotleto pay some attention to the question of the possibility of cognition17 On the structure and underlying rationale of the series of treatises assembled under the headingParva naturalia see van der Eijk (1994) 68–72; see also Morel (2000) 10–24 and (2002b).18 For a discussion of this ‘Preface’ see van der Eijk (1994) 68–72.