THE BELFAST ADDEESS. 193 



be a mere link in that chain of eternal causation which 

 holds so rigidly in nature, violently broke the chain by 

 making nature, and all that it inherits, an apparition 

 of the mind.* And it is by no means easy to combat 

 such notions. For when say ' I see you/ and that there 

 is not the least doubt about it, the obvious reply is, that 

 what I am really conscious of is an affection of my own 

 retina. And if I urge that my sight can be checked 

 by touching you, the retort would be that I am equally 

 transgressing the limits of fact; for what I am really 

 conscious of is, not that you are there, but that the 

 nerves of my hand have undergone a change. All we 

 hear, and see, and touch, and taste, and smell, are, it 

 would be urged, mere variations of our own condition, 

 beyond which, even to the extent of a hair's breadth, 

 we cannot go. That anything answering to our im- 

 pressions exists outside of ourselves is not a fact, but 

 an inference, to which all validity would be denied by 

 an idealist like Berkeley, or by a sceptic like Hume. 

 Mr. Spencer takes another line. With him, as with 

 the uneducated man, there is no doubt or question as 

 to the existence of an external world. But he differs 

 from the uneducated, who think that the world really 

 is what consciousness represents it to be. Our states 

 of consciousness are mere symbols of an outside entity 

 which produces them and determines the order of 

 their succession, but the real nature of which we can 

 never know, f In fact, the whole process of evolution is 



* Bestimmung des Menschen.' 



f In a paper, at once popular and profound, entitled ' Recent 

 Progress in the Theory of Vision,' contained in the volume of 

 Wt uivs by Helmholtz, published by Longmans, this symbolism 

 of our states of consciousness is also dwelt upon. The impressions 

 of sense are the mere signs of external things. In (his pnper 

 flelmholtz contends strongly against the view thnt the conscious- 

 ness of space is inborn ; and he evidently doubts the power of the 



