FALLACinS OF SIMPLE INSPF.CTION. 459 



withstanding is but an augurial terror, according to tliat received ex- 

 pression, Inauspicatum dat iter ohUittis /rpu.s. And the ground of the 

 conceit was prt)l)aV)ly no greater than tliis, tlmt a fearful animal pjussing 

 by us portended unto us something to be feared ; as upon tli«^ Uke 

 consideration the meeting of a fox presaged some future imposture," 

 Such superstitions as these last must be the result of stutly; they are 

 too recondite for natural or spontaneous growth. But when the at- 

 tempt w:is once made to construct a science of predicticms, any asso- 

 ciation, though never so faint or remote, by which an object could bo 

 connected in however far-fetched a manner with ideas either of pros- 

 perity or of danger and misfortune, was enough to determine its being 

 classed among good or evil omens. 



An example of rather a different kind from any of these, but falling 

 under the same principle, is the famous attempt, on which so much 

 labor and ingenuity were expended by the alchemists, to make gold 

 potable. The motive to this was a conceit that potable gold could be 

 no other than the universal medicine : and why gold ? Because it was 

 so precious. It must have all marvelous properties as a physical 

 substance, because the mind was already accustomed to marvel at it. 



From a similar feeling, " every substance," says Dr. Paris,* " whose 

 origin is involved in mysterj', has at different times been eagerly ap- 

 plied to the purposes of medicine. Not long since, one of those 

 showers which are now known to consist of the excrements of insects, 

 fell in the north of Italy ; the inhabitants regarded it as manna, or 

 some supernatural panacea, and they swallowed it with such avidity, 

 that it was only by extreme address that a small quantity was obtained 

 for a chemical examination." The superstition, in this instance, though 

 doubtless partly of a religious character, probably in part also arose 

 from the prejudice that a woiidedul thing must of course have wonder- 

 ful properties. 



§ 3. The instances of d priori fallacy which we have hitherto cited, 

 belong to the class of vulgar errors, and do not now, nor in any but a 

 rude age ever could, impose upon minds of any consideraV»le attain- 

 ments. But those to which we are about to proceed, have been, and 

 still are, all but universjdly prevalent evi;n among philosophers. The 

 same disposition to give objectivity to a law of the mind — to suppose 

 that what is true of our ideas of things must be true of th(> things them- 

 selves — exhibits itself in many of the most accredited modes of philo- 

 sophical investigation, both on physical and on metaphysical subjects. 

 In one of its most undisguised manifestations, it embodies itself in two 

 maxims, wliicb lay claim to axiomatic truth : Tiling* which we cannot 

 tliink of together, cannot coexist ; and, Things which we cannot help 

 thinking of together, must coexist. I am not sure that the maxims 

 were ever expressed in the.se precise words, but the history Ixjth of 

 philosophy and of popular opinions abounds with exemplifications of 

 both forms of the doctrine. 



To begin with the latter of them : Things which we cannot think of 

 except together, must exist together. This is assumed in the many 

 reasonings of philosophers which conclude that A must accomi)any B 

 in point of fact, because " it is involved in the idea." Such thinkers 



* Pharmacologia, Historical Introduction, p. 16 



