APOLOGY FOR THE BELFAST ADDRESS. 499 
chimeras, which astound all thinking men, it did not 
appear to me extravagant to claim the public tolerance 
for an hour and a half, for the statement of more reason- 
able views views more in accordance with the verities 
which science has brought to light, and which many weary 
souls would, I thought, welcome with gratification and 
relief. 
But to come to closer quarters. The expression to 
which the most violent exception has been taken is this: 
" Abandoning ull disguise, the confession I feel bound to 
make before you is, that I prolong the vision backward 
across the boundary of the experimental evidence, and 
discern in that Matter which we, in our ignorance, and 
notwithstanding our professed reverence for its Creator, 
have hitherto covered with opprobrium, the promise and 
potency of every form and quality of life." To call it a 
"chorus of dissent," as my Catholic critic does, is a mild 
way of describing the storm of opprobrium with which 
this statement has been assailed. But the first blast of 
passion being past, I hope I may again ask my opponents 
to consent to reason. First of all, I am blamed for cross- 
ing the boundary of the experimental evidence. This, I -> 
reply, is the habitual action of the scientific wind at least 
of^ that portion of it which applies itself to physical inves- 
tigation. Our theories of light, heat, magnetism, and " 
electricity, all imply the crossing of this boundary. My 
paper on the " Scientific Use of the Imagination," and my 
" Lectures on Light," illustrate this point in the amplest 
manner; and in the article entitled " Matter and Force" 
in the present relume I have sought, incidentally, to make 
clear, that in physics the experiential incessantly leads 
to the ultra-experiential; that out of experience there 
always grows something finer than mere experience, and 
that in their different powers of ideal extension consists, 
for the most part, the difference between the great and the 
mediocre investigator. The kingdom of science, then, 
cometh not by observation and experiment alone, but is 
completed by fixing the roots of observation and experiment 
iii a region inaccessible to both, and in dealing with which 
Ave are forced to fall back upon the picturing power of the 
mind. 
Passing the boundary of experience, therefore, does not, 
in the abstract, constitute a sufficient ground for censure. 
