Besides, according to these very authorities there are particulars relating to locality and to season. When they are discussing what should be done by men in health, they prescribe the avoidance of cold, heat, surfeit, fatigue, venery, especially in sickly localities and seasons; in such places and seasons rest is to be taken, particularly when one feels a sense of oppression, and neither the stomach is to be disturbed by an emetic, nor the bowels by a purge. Such generalities are indeed true: none the less they descend from them to certain particular characteristics, unless they would persuade us that climate and season are to be taken into consideration by those in health but not by the sick, the very persons in whom all such observance is by so much the more necessary, the more that their weakness is liable to all attacks. Nay, even in the same patient, the particular characteristics of a disease are very various, and those who have been treated for a time in vain by the ordinary remedies have been often restored by contrary ones. And in the giving food too there are many distinctions to be noted; I will content myself with one instance. For hunger is more easily borne by an adult than by a boy, more easily in a dense than in a thin atmosphere, more easily in winter than in summer, more easily by one accustomed to a single meal than by one used in addition to one at midday,[p. 41] more easily when sedentary than when in active exercise; and often it is necessary to hurry on the meal in the case of one who is intolerant of hunger. Hence I conjecture that he who is not acquainted with the peculiar characteristics has merely to consider the general ones; and he who can become acquainted with peculiarities, whilst insistent upon them, ought not to neglect generalities as well; and consequently, presuming their state to be equal, it is more useful to have in the practitioner a friend rather than a stranger.
Therefore, to return to what I myself propound, I am of opinion that the Art of Medicine ought to be rational, but to draw instruction from evident causes, all obscure ones being rejected from the practice of the Art, although not from the practitioner's study. But to lay open the bodies of men whilst still alive is as cruel as it is needless; that of the dead is a necessity for the learner, who should know positions and relations, which the dead body exhibits better than does a living and wounded man. As for the remainder, which can only be learnt from the living, actual practice will demonstrate it in the course of treating the wounded in a somewhat slower yet much milder way.