And hence we are led to some considerations on syncope, an affection exemplifying in a less degree the same phenomena, which in a greater one, is offered us in cases of sudden death. The causes of syncope are referred by Cullen to two general heads: Of these there is one set which according to him affect the brain, another set which affect the heart. Among the first, he places the more violent impulses on the mind, and various evacuations, but it is easy to prove, that the brain is only secondarily affected in syncope produced by passion, and that it is the heart, whose functions in all these cases are the first to be interrupted. The following considerations, if I am not mistaken, will leave but little doubt on this head. 1st.--I have proved, in speaking of the passions, that they never affect the brain in the first place; that the action of this organ, in consequence of their development, is only secondary, and that every thing relating to our moral affections has its seat exclusively in the organic life. 2dly.--The phenomena of syncope when produced by lively emotion, are similar in every respect to those of syncope, the effect of polypi or dropsy of the pericardium, but in the latter, the affection of the heart is the primary one, and should in consequence be the same in the former sort of syncope. 3dly.--At the moment when syncope takes place, we feel the attack at the heart, and not in the brain. 4thly.--In consequence of lively passions, which may have occasioned syncope, we find that the heart and not the brain becomes diseased, nothing is more common than organic affections of the former from sorrow, &c. The different sorts of madness, which are produced by the same cause, for the most part have their principal seat in some of the viscera of the epigastrium, and in such case, the irregularity of the cerebral action is the sympathetic effect of the profound affection of the internal organ.[76] 5thly.--I shall prove hereafter, that the cerebral system does not exert any direct influence over that of the circulation; that there is no reciprocity between the two, and that the changes of the first are not followed by similar changes in the second, however much the changes of the second may modify the first. Destroy all nervous communication between the brain and the heart, and the circulation will go on as usual; but if the vascular communications be intercepted, the cerebral action vanishes at once. 6thly.--Palpitations and other irregular movements of the heart are often the effect of the same causes, which in some individuals are the occasion of syncope. In such cases, it is easy to discover the seat of the affection, and such smaller effects of the passions on the heart, are very well calculated to throw light upon the nature of the greater.[77]