246 THOUGHTS ON THE NATURE AND ORIGIN OF FORCE. 



constituted ; imless operations have been or are to be performed which 

 are impossible under the laws to which the kuow^n o>perations going on 

 at present in the material world are subject/^ And in a communication 

 to the British Association in September, 18G1, on " Physical Considera- 

 tions regarding the Possible Age of the Sun's Heat," Professor Thom- 

 son repeats, that " although mechanical energy is indestructible, there 

 is a universal tendency to its dissipation, which produces gi^dual aug- 

 mentation and diffusion of heat, cessation of motion, and exhaustion of 

 potential energy, through the material uuiverse.''t 



In glancing thus cursorily at the nature of force, and its more strik- 

 ing manifestations, it is hardly necessaiy to allude to the now recognized 

 correlation of the organic and so-called " vital"' forms of power with 

 the purely i)hysical and kinetic. It has been reserved to our own day 

 to see established in all its fullness the grand dynamic equation — 

 '• Causa mqiuit ejfectumP It has been shown by the most varied series 

 of experiments and observations that physiological, like mechanical 

 processes, are i^ossible only on the sufficient consumption of fuel 5 that 

 growth, and development, and muscular movement are derived from the 

 oxidation of carbon and of tissue, whose products may be accurately 

 measured : and are all but phases of the ever-changing, never-dying 

 energy of Nature. 



Perhaps each one who should consult his " consciousness" alone (that 

 witness so important to the metaphysician) would feel a conviction that 

 when he strikes a blovv' he is exerting an original and self-derived 

 power. And yet it is certain that the w ill of an Alexander, a Bonaparte, 

 or a Bismarck, would be as impotent to move a grain of sand without 

 an adequate supi)ly of pre-existing external force placed at its disposal, 

 as to launch the Great Eastern from its ways without a similar s^pplJ^t 



*i. E. D. Phil. Macf., October, 1852, Vol. IV, p. 304. 



t Report of Thirty-lirst Meeting, &c., Notices ami Abstracts, -page 27. (Republished 

 ill the L. E. D. Phil. Mag., February, 1862, Vol. XXIII, p. 158.) 



t It is proper to notice here a caution which has been suggested, that the will, though 

 aduiitted to be merely a starter or director of the animal store of material force, must 

 still exert and therefore originate the power, however small, necessary for such initia- 

 tion. Sir John Herschel, in au essay "On the Origin of Force," remarks: "The actual 

 force necessary to be onginaied to give rise to the utmost imaginable exertion of ani- 

 mal power in any case may be no greater than is required to remove a single material 

 molecule from its place through a space inconceivably minute ; no more in comparison 

 with the dynamical force disengaged directly or indirectly by the act than the pull of 

 a hair-trigger in comparison with the force of the mine which it explodes. But with- 

 out the power to make some material disposition, to originate some movement, or to 

 change, at least temporarily, the amount of dynamical force appropriate to some one or 

 more material molecules, the mechanical results of human or animal volition are incon- 

 ceivable. It matters not that we are ignorant of the mode in which this is performed. 

 It suffices to bring the origination of dynamical power, to however small an extent, 

 within the domain of acknowledged personahty." (The Fortiiighili/ Pevicw for July 1, 

 1865, Vol. I, p. 439.) 



This directing capacity of the animal will, like that directing impulse which presides 

 over the entire domain of organic evolution, eludes all analysis, and hence has no 

 recognized dynamic equivalent. Without attempting to discuss here this very abstruse 



