68 MK. J. HASSELL 



An illustration taken from the science of physiology may 

 be useful here. Suppose the assertion to be made that the 

 human lungs exhale carbonic acid gas. A person altogether 

 ignorant of the science might say, I cannot see this particular 

 gas, how then am I to know that what is asserted is true? 

 The proof would have to be worked out in the following way. 

 Some lime-water having been procured, the individual would 

 be directed to breathe through a glass tube which had one of 

 its ends immersed in the solution. After breathing for a few 

 seconds, he would be asked to say what he observed. Namely, 

 that the water had assumed a milky appearance ; and this, he 

 would be told, was due to the union of carbonic acid gas with 

 the lime held in solution by the water — thus forming a car- 

 bonate of lime — chalk — which is of a white colour. As this 

 change was due to the presence of carbonic acid gas, which he 

 had himself put in by breathing, it must have had its origin 

 in the lungs ; and so it would be proved beyond doubt that the 

 human lungs do exhale carbonic acid gas. So much, then, 

 for the physical fact. But then there is the mental fact, the 

 sense of whiteness. How comes this ? Is that due to a phy- 

 sical act or a mental phenomenon ? Let us see. Colour is 

 produced, we are told, by the length of the rays of light as 

 they impinge upon the retina of the eye, and set up certain 

 currents, which ultimately reach the brain. All, then, that the 

 brain receives is motion, but mere motion is not whiteness. 

 How, then, comes the consciousness of the fact? In other 

 Avords, how can we pass from the mere fact of a nerve-motion 

 •to the fact of consciousness ? Only, we think, on the hypo- 

 thesis of an interpreting mind. We conclude, therefore, that 

 there is such a phenomenon as mind. But whence this mind? 

 Mind can only be originated by mind. No effort enables us 

 to think that the motion of a nerve-molecule could ever give 

 birth to that immaterial mind which we have seen present in 

 the individual — that mere motion is intelligent is indeed " un- 

 thinkable.^^ Even Professor Tyndall admits this. His words 

 are well worth careful consideration. He says : — 



" What is the causal connexion between molecuUxr motions and states 

 ot consciousness ? My answer is, I do not see the connexion, nor am I 

 acquainted with anybody who does. It is no explanation to say that the 

 objective and subjective are two sides of one and tlie same phenomenon. 

 "Why should the plietiomenon have two sides ? This is the very core of the 

 difficulty. There are plenty of molecular motions which do not exhibit 

 this two-sidedness. Does Avater think or feel when it runs into frost-ferns 

 upon a window-jiane ? If not, why should the molecular motion of the 

 brain be yoked to this mysterious companion — consciousness ? We can 

 form a coherent picture of all the purely physical processes, — the stirring 

 of the brain, the thrilling of the nerves, the discharging of the muscles, 



