FALLACIES OF SIMPLE INSPECTION 



503 



and the flowers of saffron that of the 

 bile." 



The early speculations respecting 

 the chemical composition of bodies 

 were rendered abortive by no circum- 

 stance more than by their invariably 

 taking for granted that the properties 

 of the elements must resemble those 

 of the compounds \<?hich were formed 

 from them. 



To descend to more modern in- 

 stances ; it was long thought, and 

 was stoutly maintained by the Carte- 

 sians, and even by Leibnitz, against 

 the Newtonian system, (nor did New- 

 ton himself, as we have 8een, contest 

 the assumption, but eluded it by an 

 arbitrary hypothesis,) that nothing 

 (of a physical nature at least) could 

 account for motion except previous 

 motion ; the impulse or impact of 

 some other body. It was very long 

 before the scientific world could pre- 

 vail upon itself to admit attraction 

 and repulsion {i.e. spontaneous ten- 

 dencies of particles to approach or 

 recede from one another) as ultiniate 

 laws, no more requiring to be ac- 

 counted for than impulse itself, if 

 indeed the latter were not, in truth, 

 resvolvable into the former. From the 

 same source arose the innumerable 

 hypotheses devised to explain those 

 classes of motion which appeared more 

 mysterious than others because there 

 was no obvious mode of attributing 

 them to impulse ; as, for example, the 

 voluntary motions of the human body. 

 Such were the interminable systems 

 of vibrations propagated along the 

 nerves, or animal spirits rushing up 

 and down between the muscles and 

 the brain, which, if the facts could 

 have been proved, would have been 

 aa important addition to our know- 

 ledge of physiological laws ; but the 

 mere invention or arbitrary supposi- 

 tion of them could not, unless by the 

 strongest delusion, be supposed to 

 render the phenomena of animal life 

 more comprehensible or less mysteri- 

 ous. Nothing, however seemed satis- 

 factory but to make out that motion 

 was caused by motion ; by something 



like itself. If it was not one kind of 

 motion, it must be another. In like 

 manner it was supposed that the 

 physical qualities of objects must 

 arise from some simi-ar quality, or 

 perhaps only some quality bearing 

 the same name, in the particles or 

 atoms of which the objects were com-' 

 posed ; that a sharp taste, for ex- 

 ample, must arise from sharp par- 

 ticles. And reversing the inference, 

 the effects produced by a phenomenon 

 must, it was supposed, resemble in 

 their physical attributes the pheno- 

 menon itself. The influences of the 

 planets were supposed to be analo- 

 gous to their visible peculiarities : 

 Mars, being of a red colour, portended 

 fire and slaughter, and the like. 



Passing from physics to meta- 

 physics, we may notice among the 

 most remarkable fruits of this d 

 priori fallacy two closely analogous 

 theories, employed in ancient and 

 modern times to bridge over the 

 chasm between the world of mind 

 and that of matter : the species sen- 

 sihilcs of the Epicureans, and the 

 modern doctrine of perception by 

 means of ideas. These theories are, 

 indeed, probably, indebted for their 

 existence not solely to the fallacy in 

 question, but to that fallacy combined 

 with another natural prejudice already 

 adverted to, that a thing cannot act 

 where it is not. In both doctrines 

 it is assumed that the phenomenon 

 which takes place in us when we see 

 or touch an object, and which v/e 

 regard as an effect of that object, or 

 rather of its presence to our organs, 

 must of necessity resemble very closely 

 the outward object itself. To fulfil 

 this condition, the Epicureans sup- 

 posed that objects were constantly 

 projecting in all directions impal- 

 pable images of themselves, which 

 entered at the eyes and penetrated 

 to the mind ; while modern meta- 

 physicians, though they rejected this 

 hypothesis, agreed in deeming it neces- 

 sary to suppose that not the thing 

 itself, but a mental image or repre- 

 sentation of it, was the direct object 



