1885.] The Relations of Mind and Matter. 541 
is usual to ascribe to consciousness. In fact, the plant world is 
not utterly destitute of such motor powers. The mycelium of 
the Myxomycetes so closely simulates the Amcebze in its motions 
that it is difficult or impossible to distinguish it from the latter. 
Yet it is but a plant in motion, and is undoubtedly unconscious, 
Again the white blood corpuscles of animals are also indistin- 
guishable from Amoebz in character and habits; yet we can 
scarcely credit each of them with conscious life. Ata higher 
level in plant life we again meet with motor powers. Thus the 
carnivorous plants display characteristics not unlike those seen in 
the polyps; yet they are unquestionably unconscious, and we 
might safely ascribe a similar unconsciousness to the polyps and 
all other animals of similarly low grade. 
Thus if we begin at the lower levels of organic life, and trace 
nature upward in her development, it is very difficult to perceive 
where the influence of heredity and natural selection ceases to 
act and conscious choice enters into life as an element. On the 
other hand if we commence with the conscious life of man, and 
trace nature downwards, it is equally difficult to decide where 
consciousness ends. For at a certain intermediate level the phe- 
nomena observed might safely be ascribed to either conscious or 
unconscious action. Both seem capable of producing them, and 
it is utterly impossible to decide, with our present knowledge of 
the subject, which does produce them. Where there is evidence 
of unusual choice in some animal, or marked variation from its 
hereditary habits, we can be sure of conscious activity. On the 
other hand, where there is no nervous system, and no cerebral 
organ or force reservoir, we may reasonably question the exist- 
ence of psychical powers. And yet, even in this extreme case, 
we cannot positively declare that consciousness does not exist. 
In fact, although we may imagine that we are considering two 
conditions of whose actual existence we have equal knowledge, 
such is really not the case. Man finds in himself his only stand- 
ard of comparison. We know that within ourselves conscious- 
ness exists, and oversees, though it may not directly control, the 
great mass of our actions. We know, on the other hand, that 
many of our actions are performed unconsciously. In consider- 
ing the activities of lower nature, then, we cannot actually know 
that consciousness may not, to some extent, accompany them. 
We have some warrant to say that the unconscious action, which 
