186 Charles W. Hargitt 
And though one may not be able to demonstrate a distinctive kind 
of energy back of such phenomena, measurable by any known 
standard, this does not vitiate the essentially scientific nature of 
such a postulate as a working hypothesis. Indeed, in so far as 
the bevavior of man and higher vertebrates is concerned there has 
been small hestitation in assuming the operation of psychic factors. 
But who shall draw the line in the scale of life where such cease 
and where chemico-physical become dominant or absolute f 
Granted the existence and efficiency of psychic energy at any 
point in the field of behavior, why shall its rdle betabooed as in any 
sense an abandonment of the problem, or as disloyalty to the 
scientific method? It is not vital by what term we may choose 
to designate these extra-mechanical factors. Whether they be 
designated as “associative memory,” “psychoid, ” “entelechy,” 
“mnemism” or “physiological states,”’ is of small consequence. 
But that there is back of such terminology subjective reality, of 
which behavior is the varied expression, is of profoundest import. 
And this, as I understand, is the fundamental contention of neo- 
vitalism as interpreted by Driesch. 
The writer believes there is a growing conviction among many 
biologists that the declaration of Driesch that the “mechanical 
theory has failed all along the line,” is not without strong sup- 
port. In confirmation of this it may be pertinent to briefly refer 
to a few of the more recent and emphatic of these. Among them 
attention may be directed to the recent presidential address of 
Dr. Francis Darwin before the British Association for the Advance- 
ment of Science. In this address Dr. Darwin does not hesitate 
to predicate the operation of psychic factors in the behavior of 
plants, radical as this may be regarded by certain advocates of the 
mechanical view. Facing the age-long question as to the presence 
of consciousness in lower organisms, Darwin says:’ “It is im- 
possible to know whether or not plants are conscious; but it is 
consistent with the doctrine of continuity that in all living things 
there is something psychic, and if we accept this view we must 
believe that in plants there exists a faint copy of what we know 
8 Science, September 18, 25, 1908. 
