3728 NOTES: 
mass can do this for a considerable time, and if its absorp- 
tion of new matter more than replaces that lost by decom- 
position, and if it is of such a nature as to resist the 
mechanical or chemical forces to which it is usually exposed, 
and to retain a tolerably constant form, we term it a living 
organism. We can conceive an organism to be so con- 
stituted, and we can further conceive that any fragments, 
which may be accidentally broken from it, or which may fall 
away when its bulk has become too great for the cohesion 
of all its parts, may begin to increase anew and run the same 
course as the parent mass. This is growth and reproduction 
in their simplest forms; and from such a simple beginning 
it is possible to conceive a series of slight modifications of 
composition, and of internal and external forces, which should 
ultimately lead to the development of more complex or- 
ganisms. The Lire of such an organism may, perhaps, be 
nothing added to it, but merely the name we give to the 
result of a balance of internal and external forces in main- 
taining the permanence of the form and structure of the 
individual. The simplest conceivable form of such life would 
be the dewdrop, which owes its existence to the balance 
between the condensation of aqueous vapour in the atmo- 
sphere and the evaporation of its substance. If either is in 
excess, it soon ceases to maintain an individual existence. I 
do not maintain that vegetative life is wholly due to such a 
complex balance of forces, but only that it is conceivable as 
such. 
With consciousness the case is very different. Its 
phenomena are not comparable with those of any kind of 
matter subjected to any of the known or conceivable forces of 
nature; and we cannot conceive a gradual transition from 
absolute unconsciousness to consciousness, from an un- 
sentierit organism to a sentient being. The merest rudiment 
of sensation or self-consciousness is infinitely removed from 
absolutely non-sentient or unconscious matter. We can con- 
ceive of no physical addition to, or modification of, an un- 
conscious mass which should create consciousness; no step 
in the series of changes organised matter may undergo, 
