118 



without involving the idea of its correlate^ depth ; tlie idea of 

 parent cannot exist without involving the idea of ofFspring.^^ 

 But^ notwithstanding tliis, he almost immediately after says it 

 is " a necessary reciprocal production/-' It is manifest that the 

 idea of parent cannot exist without the idea of child, and that 

 consequently they are correlates ; but it is equally manifest that 

 they are not reciprocally productive, for while the parent pro- 

 duces the child, it would be difficult for the child ^' in its turn " 

 to jiroduce the parent : it may become a parent to another child, 

 but it cannot produce the parent from whom itself has de- 

 scended. According to Mr. Grovels own definition, the im- 

 ponderables may be, in certain cases, the condition of each 

 other's existence ; but they may not become each other. He 

 again confounds production and conversion when he says, 

 speaking of heat, light, &c., that either may produce, or be 

 convertible into, any of the others.^' Production is not con- 

 version ; the parent produces the child, but surely he is not 

 converted into the child. A seed of corn produces a full head 

 of corn, but it is not converted into it. But his language on 

 this point is so confused, he at one time making distinctions 

 without differences, and at others confounding things that 

 difi'er, that it is impossible to arrive at any distinct conception 

 of the nature of his own belief. It seems, however, to partake 

 more of the nature of conversion than of correlation ; but in 

 spite of that, we have sufficient grounds to justify the assertion 

 that while the physical forces no doubt, in certain cases, con- 

 dition the existence of each other, there is not sufficient evidence 

 to enable us to say that they are convertible into each other. 



38. The theory of the Dissipation of Energy is held by Mr. 

 Moore to be inconsistent with that of its Conservation. But here 

 lam reluctantly forced to difi'er from him. The theory is, that 

 while one mode of motion produces certain other modes, such as 

 electricitj^ electricity can reproduce motion, but not the exact 

 amount of the original motion. Some has been rendered incapable 

 of reconversion, because it has become heat, and been radiated 

 by earth into space, and thus lost for all practical purposes, or, 

 as it is called, dissipated. Still the theory of conservation 

 is theoretically consistent, inasmuch as, although allowing the 

 departure of the motion from the earth, it asserts its con- 

 tinuance in the ethereal medium filling space. While, how- 

 ever, allowing all this, we are hereby taught that conservation 

 of energy in reference to the earth, really means nothing more 

 than that energy is conserved, till it is finally lost; for Pro- 

 fessors Tait and Thomson tell us that, in consequence of the 

 energy of all the planets eventually losing its kinetic form, they 

 must creep in age by age towards the sun to a fiery end. But 



