266 MAN AND NATURE. 



of the earth, are the portions of the material inorganic 

 world with which we are connected by reciprocal rela- 

 tions essential to our very existence. No illustrations 

 are needed in proof of this general fact. But beyond it 

 lies another, equally certain though more obscure to our 

 conception, viz., the existence of certain forces, or active 

 powers of nature light, heat, electricity, gravitation, 

 &c. which we cannot define as material, though they 

 are known to us only in connexion with matter, and 

 through their several actions upon it. These so-called 

 forces (for we have at present no fitter name for 

 them), while governing and constraining in various ways 

 the power and action of Man, are in other and endless 

 ways submitted to his intelligence, and become the 

 instruments with which he works in the material 

 world. The relations of matter to force, as well as the 

 correlation of different forms of force, and the con- 

 nexion of all with organisation and vitality, are the 

 problems most strenuously pursued by the philosophers 

 of our own day. Experimental truths and metaphy- 

 sical uncertainties come here into close contact, and too 

 often engender shallow devices of language to shelter 

 imperfect knowledge. But the search after truth by 

 experiment and strict induction is now the rule of all 

 science ; and words are used by wise men but as 

 counters, to be put aside or changed when they have 

 fulfilled their temporary purposes. 



We are carrying this general view far beyond the 

 horizon which our author has been content to take as 

 his boundary. But we feel that by thus enlarging its 

 scope we give to the subject a higher purpose as a 



