S JOURNAL OF THE January, 



This proved to be the case with the notion which Coleridge 

 worked out in his " Theory of Life," — a vein which many philoso- 

 phizers had followed before his time and one which some occa- 

 sionally dig at even now. The idea they seek to develop is that 

 which Herbert Spencer himself expressed in one of his early es- 

 says, when he said: "The characteristic which, manifested in a 

 high degree, we call Life, is a characteristic manifested only in a 

 lower degree by so-called inanimate objects." 



But this conception was too indefinitely homogeneous to rest 

 quietly in Mr. Spencer's mind. We all know how it subsequently 

 evolved into the famous definition, given in his " Principles of Bi- 

 V>logy," namely, that life is " the definite combination of hetero- 

 geneous changes, both simultaneous and successive, in correspon- 

 dence with external co-existences and sequences." This idea is 

 very different from the ideas which were previously entertained 

 and which various authors had attempted to record in brief sen- 

 tences and even single words. Bichat's definition of Hfe was: 

 "the sum of the functions which resist death." De Blainville's 

 was: "the twofold internal movement of composition and decom- 

 position at once general and continuous." Lewes's was: " a series 

 of definite and successive changes, both of structure and composi- 

 tion, which take place within an individual without destroying its 

 identity." All of these definitions are open to serious objection, 

 as has been shown very clearly by Dr. Drysdale in his inaugural ad- 

 dress as President of the Liverpool Biological Society. He himself 

 proposes, as being most closely in accordance with the latest 

 development of the protoplasmic theory, the definition of life as 

 "the consumption and regeneration of protoplasm in co-operation 

 with external conditions, pabulum and stimuli," which, however, 

 he thinks may be further simplified as follows: " Life is the inter- 

 action of protoplasm with the environment." 



Now, all definitions are true only from fixed points of observa- 

 tion. They vary both in time and in space, — that is, as we pass 

 from the knowledge of one period to that of another period, or as 

 we pass from the domain of one sort of learning to the domain of 

 another. Thus, while Dr. Drysdale's definition of life seems to 

 suit pretty well the present knowledge of a worker in the micro- 

 scopical realm, I can see that it may be very unsatisfactory to the 

 biologist in a broader field and that it may be totally inadequate 



