366 



FALLACIES. 



which such an hypothesis was liable to betray the practitioner, 

 received an awful illustration in the history of the memorable 

 fever that raged at Leyden in the year 1699, and which con- 

 signed two-thirds of the population of that city to an un- 

 timely grave; an event which in a great measure depended 

 upon the Professor Sylvius de la Boe, who having just em- 

 braced the chemical doctrines of Van Helmont, assigned the 

 origin of the distemper to a prevailing acid, and declared that 

 its cure could alone [only] be effected by the copious adminis- 

 tration of absorbent and testaceous medicines."* 



These aberrations in medical theory have their exact 

 parallels in politics. All the doctrines which ascribe absolute 

 goodness to particular forms of government, particular social 

 arrangements, and even to particular modes of education, 

 without reference to the state of civilization and the various 

 distinguishing characters of the society for which they are 

 intended, are open to the same objection that of assuming 

 one class of influencing circumstances to be the paramount 

 rulers of phenomena which depend in an equal or greater 

 degree on many others. But on these considerations it is the 

 less necessary that we should now dwell, as they will occupy 

 our attention more largely in the concluding Book. 



6. The last of the modes of erroneous generalization to 

 which I shall advert, is that to which we may give the name 

 of False Analogies. This Fallacy stands distinguished from 

 those already treated of by the peculiarity, that it does not 

 even simulate a complete and conclusive induction, but con- 

 sists in the misapplication of an argument which is at best 

 only admissible as an inconclusive presumption, where real 

 proof is unattainable. 



An argument from analogy, is an inference that what is 

 true in a certain case, is true in a case known to be somewhat 

 similar, but not known to be exactly parallel, that is, to be 

 similar in all the material circumstances. An object has the 

 property B : another object is not known to have that pro- 



* Pharmacologia, pp. 39, 40. 



