32 



distinctions depend upon the possession by the 

 latter of any substantial principle of action, of 

 which the former are destitute ; or do they de- 

 pend merely upon some peculiarities in the pro- 

 perties of those matters, of which inorganic and 

 organic substances are respectively composed ? 



The term life has been commonly used with 

 the utmost vagueness, and any attempt to explain 

 its nature has been in general regarded hopeless 

 in the extreme. The authors who have written 

 on the nature of life may be arranged into two 

 great classes the one comprehending those who 

 consider it a subtle substance a real arid dis- 

 tinct agent attached to certain forms of matter, 

 and the cause of the remarkable phenomena 

 which these display ; the other comprehending 

 those who regard it as merely a certain mode of 

 being, consisting in these associated phenomena, 

 and the result of certain combinations of matter 

 placed under peculiar circumstances. 



This subject may perhaps be beyond the legi- 

 timate bounds of philosophical enquiry, and at 

 all events it is not necessary for my present pur- 

 pose to enter into a speculation so dark, and 

 possibly so dangerous. A distinctive attribute of 

 life, at least as displayed by the higher order of 

 living beings, is thought ; and it is difficult, if not 

 impossible, to conceive that this can be, either 

 directly or indirectly a property of matter : and 

 if we are thus compelled to assign to the higher 

 attributes of life, an essence distinct from that of 

 matter, we appear hardly justified in assuming 



