SIR WILLIAM Hamilton's philosophy. 69 



dangers have been made apparent only by researches subsequent to his 

 own. It is a rock on which, we have just seen, he acknowledges that 

 some previous investigators of his own school had been shipwrecked ; 

 and it is consequently difficult to see how he should have run upon it so 

 directly himself. There is room enough for conjecturing what can have 

 led him into a course, against which he has uttered such unequivocal 

 warnings ; it is possible that the true cause is to be found in what may 

 be regarded as one of the great misfortunes — perhaps Ferrier was right 

 in regarding it as " the one mistake," * — of his philosophical life, that 

 he should have dedicated his powers to the service of the Common 

 Sense school as represented by its most characteristic exponent, Dr. 

 Reid. Whether external perception be a primitive intuition of the 

 human mind or not, it was idle to refer to the ordinary and irresistible 

 convictions of mankind except to discover the fact which it is the office 

 of mental science to explain. To refer to these convictions, as if they 

 superseded all the recognized processes of science, was to foreclose the 

 very inquiries, which constitute the science of mind, into the nature 

 and the origin of mental phenomena. Sir W. Hamilton, therefore, by 

 accepting this philosophy as the highest effort of speculation, unfortu- 

 nately bound himself to shape his theory of perception into harmony 

 with it, and was accordingly forced to disallow the question with which 

 the above quotation from Schelling concludes, " "Whence comes this 

 element of immediateness and of insuperable certainly in our know- 

 ledge ? " To him our knowledge of external things is immediate ; we 

 know, and have a right to ask, nothing beyond that fact. If the argu- 

 ment from common sense be, as is maintained by Hamilton, merely a 

 reference to the ultimate and simple facts of human consciousness, then 

 the Common Sense school is indistinguishable from other schools of 

 speculation ; for there is no philosophy which does not professedly seek 

 to discover by what smallest number of ultimate and inexplicable facts 

 the phenomena of the universe may be explained, or which dreams of 

 denying these facts after they have been discovered. But when any 

 circle of inquirers distinguish themselves by their habit of appealing to 

 common sense, it is difficult to understand for what purpose such an 

 appeal can be habitually made, unless it be to array the unscientific 

 opinions that are universally current among men against speculative 

 conclusions which cannot be rebutted by the recognized methods of 



* Ferrier's Lectures and PhilosopMcal Remains, vol. I., p. 489. 



