ADDRESS, Ixxvii 



sufficient force and permanence to occasion their transmission to the offspring 

 as tendencies to similar modes of thourjld. And thus, while all admit that 

 Knowleclje cannot thus descend from one generation to another, an increased 

 aptitude for the acquirement, either of knowledge generally, or of some par- 

 ticular kind of it, may be thus inherited. These tendencies and aptitudes 

 will acquire additional strength, expansion, and permanence, in each new 

 generation, from their habitual exercise upon the materials supplied by a con- 

 tinually enlarged experience ; and thus the acquired habitudes produced by 

 the Intellectual culture of ages, wiU become " a second nature " to every one 

 who inherits them *. 



We have an illustration of this progress in the fact of continual occurrence, 

 that conceptions which prove inadmissible to the minds of one generation, in 

 consequence either of their want of intellectual power to apprehend them, or 

 of their preoccupation by older habits of thought, subsequently find a uni- 

 versal acceptance, and even come to be approved as " self-evident." Thus the 

 First Law of Motion, divined by the genius of Newton, though opposed by 

 many Philosophers of his time as contrary to all experience, is now accepted 

 by common consent, not merely as a legitimate inference from Experiment, 

 but as the expression of a necessary and universal truth; and the same 

 Axiomatic value is extended to the still more general doctrine, that Energy 

 of any kind, whether manifested in the " molar " motion of masses, or con- 

 sisting in the " molecular " motion of atoms, must continue under some 

 form or other without abatement or decay; what aU admit in regard to 

 the indestructibility of Matter, being accepted as no less true of Force, namely, 

 that as ex nihilo nil Jit, so nil Jit ad nihilumf. 



But, it may be urged, the very conception of these and similar great truths 

 is in itself a typical example of Intuition. The men who divined and enun- 

 ciated them stand out above their fellows, as possessed of a Genius which 

 could not only combine but create, of an Insight which could clearly discern 

 what Eeason could but dimly shadow forth. Granting this freely, I think 

 it may be shown that the Intuitions of individual Genius are but specially 

 exalted forms of endowments which are the general property of the Race at 

 the time, and which have come to be so in virtue of its whole previous culture. — 

 "Who, for example, could refuse to the marvellous aptitude for perceiving the 

 relations of Numbers, which displayed itself in the untutored boyhood of 

 George Bidder and Zerah Colburn, the title of an Intuitive gift? But who, 

 on the other hand, can believe that a Bidder or a Colburn could suddenly 



* This doctrine was first explicitly put fortli by Mr. Herbert Spencer; in whose 

 Philosophical Treatises it will be found most ably developed. I am glad to be able to 

 append the following extract from a letter which Mr. Jolni Mill, the great Master of the 

 Experiential School, was good enough to write to me a few months since, with reference 

 to the attempt I had made to place "Common Sense" upon this basis (Contemporary 

 Review, Feb. 1872) : — " When states of mind in no respect innate or instinctive have been 

 * frequently repeated, the mind acquires, as is proved by tlie power of Habit, a greatly 

 " increased facility of passing into those states ; and this increased facility must be owing 

 " to some change of a physical character in the organic action of the Brain. There is also 

 " considerable evidence that such acquired facilities of passing into certain modes of 

 " cerebral action can in many cases be transmitted, more or less completely, by inheritance, 

 " The limits of this power of transmission, and the conditions on which it depends, are a 

 " subject now fairly before the scientific world ; and we shall doubtless in time know much 

 " more about them than we do now. But so far as my imperfect knowledge of the subject 

 " qualifies me to have an opinion, I take much the same view of it that you do, at least 

 " in principle." 



+ This is the form in which the doctrine now known as that of the " Conservation of 

 Energy " was enunciated by Dr. Mayer, in the very remarkable Essay published by liim in 

 1845, entitled " Die organische Bewegung in ihrem Zusammenhange mit dem Stoffwechsel." 



