David Hartley

“ Inquiries after the philosopher’s stone, the longitude, &c. to which men are prompted by strong, ambitious, or covetous desires, are often both cause and effect, in respect of madness. Excessive fits of anger and fear are also found often to hurry persons into madness.
In dissections after madness the brain is often found dry, and the blood-vessels much distended; which are arguments, that violent vibrations took place in the internal parts of the brain, the peculiar residence of ideas and passions; and that it was much compressed, so as to obstruct the natural course of association. ”

“ We see that, in old persons, all the parts, even the bones themselves, waste and grow less. Why may not this happen to the brain, the origin of all, and arise from an obstruction of the infinitesimal vessels of the nervous system, this obstruction causing such a degree of opacity, as greatly to abate, or even to destroy, the powers of association and memory? At the same time vibrations, foreign to the present objects, may be excited from causes residing in the brain, stomach, &c. ”

“ And thus it appears, that all violent passions must be temporary madnesses, and all habits of them permanent ones, agreeably to the judgment of the wise and good in these things. It appears also, that violent fits of passion, and frequent recurrences of them, must, from the nature of the body, often transport persons, so that they shall not be able to recover themselves, but fall within the limits of the distemper called madness emphatically. ”

“ The dotage of old persons is oftentimes something more than a mere decay of memory. For they mistake things present for others, and their discourse is often foreign to the objects that are presented to them. ”

“ The want of the connecting consciousness in children and idiots, and indeed in maniacs of various kinds, excites our pity in a peculiar manner, this connecting consciousness being esteemed a principal source and requisite of happiness. ”

“ For hence we may conclude, that the real objects overpower the visible train from internal causes, while the delirium is in its infancy; and that the patient relapses, as soon as he is shut up in the dark, because the visible train from internal causes overpowers that which would rise up, was the person’s nervous system in a natural state, according to the usual course of association, and the recurrent recollection of the place and circumstances in which he is situated. ”

“ And as these vibrations, when the passions are not in great excess, do not much transgress the limits of pleasure, it will often happen that hypochondriac and hysteric persons shall be apt to be transported with joy from trifling causes, and be, at times, disposed to mirth and laughter. They are also very fickle and changeable, as having their desires, hopes, and fears, increased far beyond their natural magnitude, when they happen to fall in with such a state of brain as favours them. ”

“ Particularly it seems natural to expect that they should at first be much disposed to mirth and laughter, with a mixture of small inconsistencies and absurdities; that these last should increase from the vivid trains which force themselves upon the brain, in opposition to the present reality; that they should lose the command and stability of the voluntary motions from the prevalence of confused vibrations in the brain, so that those appropriated to voluntary motion cannot descend regularly as usual ”

“ The next species of alienations of the mind is melancholy. Vapours, hypochondriacal, and hysterical disorders, are comprehended under this class. The causes of it are self-indulgence in eating and drinking, and particularly in fermented liquors, want of due bodily labour, injuries done to the brain by fevers, concussions, &c., too much application of the mind, especially to the same objects and ideas, violent and long-continued passions, profuse evacuations, and an hereditary disposition; which last we may suppose to consist chiefly in an undue make of the brain. ”

“ As death approaches, the deliriums attending distempers abound with far more incoherencies and inconsistencies, than any other species of alienations of the mind; which may easily be conceived to be the natural result of the entire confusion and disorder which then take place in the nervous system. ”

“ The same perpetual recurrency of vibrations, affecting one and the same part of the brain, in nearly one and the same manner, must irritate it at last, so as to enter the limits of pain, and approach to the states peculiar to fear, anxiety, despondency, peevishness, jealousy, and the rest of the tribe of hypochondriacal passions. ”

“ Besides which it may be observed, that in dotage the person is often sluggish and lethargic; and that as a defect of the nutritive faculty in the brain will permit the sinuses to be more easily distended, so a distention of the sinuses, from this or any other cause, may impede the due nutrition of the brain. ”

“ But besides this, it seems, that, in the deliriums attending distempers, a vivid train of visible images forces itself upon the patient’s eye, and that either from a disorder in the nerves and blood-vessels of the eye itself, or from one in the brain, or one in the alimentary duct, or which is most probable, from a concurrence of all these. ”

“ When a person applies himself to any particular study, so as to fix his attention deeply on the ideas and terms belonging to it, and to be very little conversant in those of other branches of knowledge, it is commonly observed, that he becomes narrow-minded, strongly persuaded of the truth and value of many things in his own particular study, which others think doubtful or false, or of little importance, and after some time subject to low spirits, and the hypochondriacal distemper. ”

“ However, if an adult should become subject to a like erroneousness, it would evidently be one species of madness; as fatuity or idiotism is. Here the brain labours under such an original disorder, as either not to receive a disposition to the miniature vibrations in which ideas consist, and whence voluntary motions are derived, but with great difficulty ”

“ As in mad persons the vibrations in the internal parts of the brain are preternaturally increased, so they are defective in the external organs, in the glands, &c. Hence maniacs eat little, are costive, make little water, and take scarce any notice of external impressions. ”

“ The perpetual recurrency of particular ideas and terms makes the vibrations belonging thereto become more than ordinarily vivid, converts feeble associations into strong ones, and enhances the secondary ideas of dignity and esteem, which adhere to them, at the same time that all these things are diminished in respect of other ideas and terms that are kept out of view ”

“ It is moreover to be noted, that the pleasant vibrations producing this gaiety by rising higher and higher perpetually, as more wine is taken into the stomach and blood-vessels, come at last to border upon, and even to pass into, the disagreeable vibrations belonging to the passions of anger, jealousy, envy, &c. ”

“ Persons inclining to be delirious in distempers are most apt to be so in going to sleep, and in waking from sleep; in which circumstances the visible trains are more vivid, than when we are quite awake, as has been observed above. ”

“ That delirious persons have such trains forced upon the eye from internal causes, appears probable from hence, that when they first begin to be delirious, and talk wildly, it is generally at such times only as they are in the dark, so as to have all visible objects excluded ”

“ Wine, after it is absorbed, must rarefy the blood, and consequently distend the veins and sinuses, so as to make them compress the medullary substance, and the nerves themselves, both in their origin and progress ”

“ It follows from the same method of reasoning, that since the concerns of religion are infinite, so that we can never over-rate them, we ought to make the ideas, motives, and affections, of this kind, recur as often as possible. ”

“ Persons that are under the influence of strong passions, such as anger, fear, ambition, disappointment, have the vibrations attending the principal ideas so much increased, that these ideas cling together, i.e. ”