SCEPTICISM.
Credulity has been justly defined, Belief without Reason. Scepticism is its opposite, Reason without Belief and is the natural and invariable consequence of credulity: for it may be generally observed, that men who believe without reason, are succeeded by others whom no reasoning can convince; a fact which has occasioned many extraordinary and violent revolutions in the Materia Medica, and a knowledge of it will enable us to explain the otherwise unaccountable rise and fall of many useless, as well as important articles. It will also suggest to the reflecting practitioner, a caution of great moment, to avoid the dangerous fault imputed to Galen by Dioscorides, of ascribing too many and too great virtues to one and the same medicine. By bestowing unworthy and extravagant praise upon a remedy, we in reality do but detract from its reputation,[[36]] and run the risk of banishing it from practice; for when the sober practitioner discovers by experience that a medicine falls so far short of the efficacy ascribed to it, he abandons its use in disgust, and is even unwilling to concede to it that degree of merit to which in truth and justice it may be entitled; the inflated eulogiums bestowed upon the operation of Digitalis in pulmonary diseases, excited, for a time, a very unfair impression against its use; and the injudicious manner in which the antisyphilitic powers of Nitric Acid have been aggrandised, had very nearly exploded a valuable auxiliary from modern practice.
It is well known with what avidity the public embraced the expectations given by Stöerk of Vienna in 1760, with respect to the efficacy of Hemlock; every body, says Dr. Fothergill, made the extract, and every body prescribed it, but finding that it would not perform the wonders ascribed to it, and that a multitude of discordant diseases refused to yield, as it was asserted they would, to its narcotic powers, practitioners fell into the opposite extreme of absurdity, and declaring that it could do nothing at all, dismissed it at once as inert and useless. Can we not then predict the fate of the Cubebs, which has been lately restored to notice with such extravagant praise and unqualified approbation? May the sanguine advocates for the virtues of the Colchicum derive a useful lesson of practical caution from these precepts: it would be a matter of regret that a remedy which, under skilful management, certainly possesses considerable virtue, should again fall into obscurity and neglect from the disgust excited by the extravagant zeal of its supporters.
There are, moreover, those who cherish a spirit of scepticism, from an idea that it denotes the exercise of a superior intellect; it must be admitted, that at that period in the history of Europe, when reason first began to throw off the yoke of authority, it required superiority of understanding as well as intrepidity of conduct, to resist the powers of that superstition which had so long held it in captivity; but in the present age, observes Mr. Dugald Stewart, “unlimited scepticism is as much the child of imbecility as implicit credulity.” “He who at the end of the eighteenth century,” says Rousseau, “has brought himself to abandon all his early principles, without discrimination, would probably have been a bigot in the days of the league.”
FALSE THEORIES, AND ABSURD CONCEITS.
He who is governed by preconceived opinions, may be compared to a spectator who views the surrounding objects through coloured glasses, each assuming a tinge similar to that of the glass employed; thus have crowds of inert and insignificant drugs been indebted to an ephemeral popularity, from the prevalence of a false theory; the celebrated hypothesis of Galen respecting the virtues and operation of medicines, may serve as an example; it is a web of philosophical fiction, which was never surpassed in absurdity. He conceives that the properties of all medicines are derived from what he calls their elementary or cardinal qualities, Heat, Cold, Moisture, and Dryness. Each of these qualities is again sub-divided into four degrees, and a plant or medicine, according to his notion, is cold or hot, in the first, second, third, or fourth gradation; if the disease be hot, or cold in any of these four stages, a medicine possessed of a contrary quality, and in the same proportionate degree of elementary heat or cold, must be prescribed. Saltness, bitterness, and acridness depend, in his idea, upon the relative degrees of heat and dryness in different bodies. It will be easily seen how a belief in such an hypothesis must have multiplied the list of inert articles in the materia medica, and have corrupted the practice of physic. The variety of seeds derived its origin from this source, and until lately, medical writers, in the true jargon of Galen, spoke of the four greater and lesser hot and cold seeds; and in the London Dispensatory of 1721, we find the powders of hot and cold precious stones, and those of the hot and cold compound powders of pearl. Several of the ancient combinations of opium, with various aromatics, are also indebted to Galen for their origin, and to the blind influence of his authority for their existence and lasting reputation. Galen asserted that opium was cold in the fourth degree, and must therefore require some corresponding hot medicine to moderate its frigidity.[[37]]
The Methodic Sect, which was founded by the Roman physician Themison,[[38]] a disciple of Asclepiades, as they conceived all diseases to depend upon overbracing, or on relaxation, so did they class all medicines under the head of relaxing and bracing remedies; and although this theory has been long since banished from the schools, yet it continues at this day to exert a secret influence on medical practice, and to preserve from neglect some unimportant medicines. The general belief in the relaxing effect of the warm, and the equally strengthening influence of the cold bath, may be traced to conclusions deduced from the operations of hot and cold water upon parchment and other inert bodies.[[39]]
The Stahlians, under the impression of their ideal system, introduced Archœal remedies, and many of a superstitious and inert kind; whilst, as they on all occasions trusted to the constant attention and wisdom of nature, so did they zealously oppose the use of some of the most efficacious instruments of art, as the Peruvian bark; and few physicians were so reserved in the use of general remedies, as bleeding, vomiting, and the like; their practice was therefore imbecile, and it has been aptly enough denominated, “a meditation upon death.” They were however vigilant in observation and acute in discernment, and we are indebted to them for some faithful and minute descriptions.
The Mechanical Theory, which recognised “lentor and morbid viscidity of the blood,” as the principal cause of all diseases, introduced attenuant and diluent medicines, or substances endued with some mechanical force; thus Fourcroy explained the operation of mercury by its specific gravity,[[40]] and the advocates of this doctrine favoured the general introduction of the preparations of iron, especially in schirrus of the spleen or liver, upon the same hypothetical principle; for, say they, whatever is most forcible in removing the obstruction, must be the most proper instrument of cure; such is Steel, which, besides the attenuating power with which it is furnished, has still a greater force in this case from the gravity of its particles, which, being seven times specifically heavier than any vegetable, acts in proportion with a stronger impulse, and therefore is a more powerful deobstruent. This may be taken as a specimen of the style in which these mechanical physicians reasoned and practised.
The Chemists, as they acknowledged no source of disease but the presence of some hostile acid or alkali, or some deranged condition in the chemical composition of the fluid or solid parts, so they conceived all remedies must act by producing chemical changes in the body. We find Tournefort busily engaged in testing every vegetable juice, in order to discover in it some traces of an acid or alkaline ingredient, which might confer upon it medicinal activity. The fatal errors into which such an hypothesis was liable to betray the practitioner, receive an awful illustration in the history of the memorable fever that raged at Leyden in the year 1699, and which consigned two thirds of the population of that city to an untimely grave; an event which, in a great measure, depended upon the Professor Sylvius de la Boe, who having just embraced the chemical doctrines of Van Helmont, assigned the origin of the distemper to a prevailing acid, and declared that its cure could alone be effected by the copious administration of absorbent and testaceous medicines; an extravagance into which Van Helmont, himself, would hardly have been betrayed:—but thus it is in Philosophy, as in Politics, that the partisans of a popular leader are always more sanguine, and less reasonable, than their master; they are not only ready to delude the world, but most anxious to deceive themselves, and while they warmly defend their favourite system from the attacks of those that may assail it, they willingly close their own eyes, and conceal from themselves the different points that are untenable; or, to borrow the figurative language of a French writer, they are like the pious children of Noah,[[41]] who went backwards, that they might not see the nakedness which they approached for the purpose of covering.