1896.] The Biologie Origin of Mental Variety : 965 
volve, fundamentally, the evolutionary relation between biol- 
ogy and psychology; and it is for this reason that I have se- 
lected it as worthy of the present occasion. 
Plunging at once to the heart of our problem, I may state 
that there are two possible propositions regarding the funda- 
mental relation of our senses to their respective sense organs ; 
which propositions are mutually contradictory and exclusive 
of each other; which, being fundamental and contradictory, 
it is necessary to decide between, as a first step toward any 
permanent insight into the evolutionary relation between 
body and mind; yet regarding which neither science nor 
philosophy, up to the present moment, has given any least in- 
timation. It will be the main purpose of this paper to set 
forth these alternative postulates as completely as I may, 
within the limit of an hour; and if within that space we do 
not arrive at any vantage ground, where we may venture a 
guess at the proper decision between them, I trust that this 
will but the more emphasize their vast and crucial signifi- 
cance. To venture a prophecy, I may state that the indis- 
pensible solution of these two postulates is not likely to be 
reached for many years to come, nor until wider discussions 
and further reaching investigations shall have been ploughed 
under them, than now cover the fields of the great Weissman- 
Lamarck controversy. 
The first of these postulates may be stated as follows: In 
the light of the little knowledge we as yet possess, it is open 
to conceive that, in the beginning of the present epoch of ani- 
mal evolution, crude or primary protoplasm was sensitive not 
only to all the forms of physical stimulation which now pro- 
duce sensory responses in us (i. e., sight, sound, taste, smell, 
touch, temperature, muscle, and other sensations), but was 
also capable, in response to appropriate stimuli, of an infinite, 
or x number of other forms of sensation which we know 
nothing about. In accord, and in illustration of this possi- 
bility, we may conceive that the simplest amorphous creatures 
now actually experience an infinite variety of transient and 
elementary sensations, including the few we have and a mul- 
titude of others that we never have. 
