332 THE GRAMMAR OF SCIENCE 



enforce a routine, nor have we sufficient grounds as yet to 

 definitely attribute this routine to the perceptive faculty. 

 It remains for the present the fundamental mystery of 

 perception, but it is the basis upon which all scientific 

 knowledge is built. Science is the description in con- 

 ceptual shorthand (never the explanation) of the routine 

 of our perceptual experience. If this be true, it follows 

 that the task of the biologist is to describe in conceptual 

 shorthand (not to explain) the sequences of certain classes 

 of sense-impressions. The problem of whether life is or 

 is not a mechanism is thus not a question of whether the 

 same things, " matter " and " force," are or are not at the 

 back of organic and inorganic phenomena — of what is at 

 the back of either class of sense-impressions we know 

 absolutely nothing — but of whether the conceptual short- 

 hand of the physicist, his ideal world of ether, atom, and 

 molecule, will or will not also suffice to describe the 

 biologist's perceptions of life. 



The mystery in the routine of sense -impressions is 

 precisely the same whether those sense-impressions belong 

 to the class of living or to that of lifeless groups. Life 

 as a mechanism would be purely an economy of thought ; 

 it would provide the great advantages which flow from 

 the use of one instead of two conceptual shorthands, but 

 it would not " explain " life any more than the law of 

 gravitation explains the elliptic path of a planet (p. 135). 

 As we have — to speak paradoxically — no sense which 

 can reach anything behind sense-impressions, no " meta- 

 physical sense " which enables us to perceive that supposed 

 entity " matter," so we have no special sense which enables 

 us to perceive another supposed entity, " life." ^ Life and 

 lifeless are merely class names for special groups of 

 sense-impressions. When, therefore, we assert " matter " 

 as the substratum of one group of sense-impressions and 

 " life " as the substratum of another, and " explain " life 

 by aid of matter and its attribute " force," we are simply, 

 albeit often unconsciously, wallowing in the Stygian creek 



1 The "'sense of consciousness," if so it can be called, is hardly a special 

 sense of life, for consciousness and life are not equivalent ternrs. 



