ADVANCEMENT OF LEARNING 109 



ternal cause, as also usually happens from an external one, 

 there the external action passes into a dream. Thus the 

 stomach may be oppressed by a gross internal vapor, as well 

 as by an external weight ; whence those who have the night- 

 mare dream that a weight is laid upon them, with a great con- 

 currence of circumstances. So, again, the viscera being equal- 

 ly tossed by the agitation of the waves at sea, as by a collection 

 of wind in the hypochondria, hence melancholy persons fre- 

 quently dream of sailing and tossing upon the waters ; and in- 

 stances of this kind are numerous. 



The second part of the doctrine of union, which we call im- 

 pression, is not yet reduced to an art; and but occasionally 

 mentioned by writers. This also has two parts : as consider- 

 ing, ist, how, and to what degree, the humors and constitu- 

 tion of the body may affect the soul, or act upon it ; and 2d, 

 how, and to what degree, the passions and apprehensions of the 

 soul may affect and work upon the body. The first of these 

 we sometimes find touched in medicine; but it has strangely 

 insinuated itself into religion. Physicians prescribe remedies 

 for the diseases of the mind, viz., madness, melancholy, etc., as 

 also to cheer the spirits, strengthen the memory, etc. ; but for 

 diet, choice of meats and drinks, washings, and other obser- 

 vances relating to the body, they are found immoderately in the 

 sect of the Pythagoreans, the Manichean heresy, and the law 

 of Mahomet. There are, also, numerous and strict ordinances 

 in the ceremonial law, prohibiting the eating of blood and fat, 

 and distinguishing the unclean animals from the clean for 

 food.' Even the Christian religion, though it has thrown off 

 the veil of ceremonies, still retains the use of fasting, abstinence, 

 and other things that regard the subjection and humiliation of 

 the body ; as things not merely ritual, but advantageous. The 

 root of all these ordinances, besides the ceremony and exercise 

 of obedience, is, that the soul should sympathize and suffer 

 with the body. And if any man of weaker judgment thinks that 

 such macerations question the immortality, or derogate from 

 the sovereignty of the soul, let him find an answer in the in- 

 stances, either of an infant in its mother's womb, which shares 

 in the vicissitudes, and yet is distinct from its mother's body, 

 or of monarchs, who, though in possession of absolute power, 

 are frequently influenced and swayed by their servants. 



The other part, which considers the operations of the soul 



