TRANSACTIONS OF THK SECTIONS. 7 



tends to develope what are called Scientific Heresies. No doubt such charges are 

 broug-ht more usually against other Sections than against this ; but Section A haa 

 not been held blameless. It seems to me that the proper answer to aU such charges 

 will be very simply and easily given, if we merely show that in our reasonings 

 from observation and experiment we invariably confine our physical conclusions 

 strictly to matter and energy (things which we can weigh and measure) in their 

 multiform combinations. Excepting that which is obviously purely mathematical, 

 whatever is certainly neither matter nor energy, nor dependent upon these, is not a 

 subject to be discussed here, even by implication. All our reasonings in Physics must, 

 so far as we know, be based upon the assumption, founded on experience, that in 

 the universe, whatever be the epoch or the locality, under exactly similar circum- 

 stances exactly similar results will be obtained. If this be not granted there is an 

 end of Physical Science, or, rather, there never could have been such a Science *. 

 To use the word " Heresy" with reference to purely phj^sical reasonings about 

 Geological Time, or matters of that kind, is nowadays a piece of foUy which even 

 Galileo's judges, were they alive, would shrink from, as calculated to damage none 

 but themselves and the cause which of old they, according to their lights, very 

 natui-ally maintained. 



There must alwaj's be wide limits of uncertainty (unless we choose to look upon. 

 Physics as a necessarily finite Science) concerning the exact boundary between the 

 Attainable and the Unattainable. One herd of ignorant people, with the sole 

 prestiffe of rapidly increasing numbers, and with the adhesion of a few fanatical 

 deserters from the ranks of Science, refuse to admit that all the phenomena even 

 of ordinaiy dead matter are strictly and exclusively in the domain of physical 

 science. On the other hand, there is a numerous group, not in the slightest degree 

 entitled to rank as Physicists (though in general they assume the proud title of 

 Philosophers), who assert that not merely Life, but even Volition and Con- 

 sciousness are mere physical manifestations. These opposite errors, into neither 

 of which is it possible for a genuine scientific man to fall, so long at least 

 as he retains his reason, are easily seen to be very closely allied. They are both 

 to be attributed to that Credulity which is characteristic alike of Ignorance and 

 of Incapacity. Unfortunately there is no cure ; the case is hopeless, for great 

 ignorance almost necessarily presumes incapacity, whether it show itself in the com- 

 paratively harmless folly of the Spiritualist or in the pernicious nonsense of the 

 Materialist. 



Alike condemned and contemned, we leave them to their proper fate — oblivion ; 

 but still we have to face the question, where to draw the line between that which 

 is physical and that which is utterly beyond physics. And, again, our answer is — 

 Experience alone can teU us ; for experience is our only possible guide. If we at- 

 tend earnestly and honestly to its teachings, we shall never go far astray. Man has 

 been left to the resources of his intellect for the discovery not merely of physical 

 laws, but of how far he is capable of comprehending them. And oiu* answer to 

 those who denoimce our legitimate studies as heretical is simply this, — A revela- 

 tion of any thing which we can discover for ourselves, by studying the ordinary 

 course of natiu'e, would be an absurdity. 



A profoimd lesson may be learned from one of the earliest little papers of 

 President, published while he was an undergraduate at Cambridge, where he shows 

 that Fourier's magnificent treatment of the Conduction of Heat leads to formulai 

 for its distribution which are intelligible (and of course capable of being fiUly 

 verified by experiment) for all time future, but which, except in particular cases, 

 when extended to time past, remain intelligible for a finite period only, and then 



* It might be possible, and, if so, perhaps interesting, to speculate on the results of 

 secular changes in physical laws, or in particles of matter which are subject to them, but 

 (so far aa experience, which is our only guide, has taught us since the beginning of modern 

 science) there seems no trace of such. Even if there were, as these changes must be of 

 necessity extremely slow (because not yet even suspected), we may reasonably expect, ft-om 

 the analogy of the history of such a question as gravitation, especially in the discovery of 

 Neptune, that our work, far from becoming impossible, will merely become considerably 

 more difficult as well as more laborious, but, on that account, all the more creditable when 

 successfully carried out. 



