P sychology. 551 
PSYCHOLOGY. 
THE RELATION OF WILL TO THE CONSERVATION OF ENERGY.! 
—It is generally supposed that the designed movements of animals 
exhibit the quality of design by reason of a direct influence exercised 
by conscious states. It is supposed that an animal eats and drinks 
because it feels hungry and thirsty; that it changes its position 
because it feels that position to be uncomfortable, on account of 
muscular weariness, unpleasant temperature, or some other reason 
which is consciously felt by it. Such acts are termed voluntary. 
They are distinguished from the automatic, which are performed 
either in the absence of consciousness of them or without that rela- 
tion of consciousness to them which is seen in the voluntary acts. 
The peculiar influence exercised by conscious states over acts is 
termed the will. Ordinary will must be distinguished from “ free 
will,” since its action is a necessary outcome of “ motives” or rea- 
sons which pre-exist in the mind ; while “free will” is supposed to 
Spontaneous in its action. With the latter supposititious faculty 
I have nothing to do in the present paper. 
The physiological action of will is as follows, so far as it has been _ 
possible to trace it. An impression or stimulus received by a sen- 
sory nerve—generally at the surface of the body—is conveyed by it 
to the posterior column of the chorda spinalis, and is thence trans- 
mitted through the optic thalamus. to some point in the gray tissue 
of the posterior lobe of the cerebral hemisphere. Thence a stimulus 
18 conveyed by some of the fibres of the white substance to the 
anterior ee of the gray cortex. Thence it returns downwards, 
conducted by white fibres, to the corpus striatum, and thence to the 
anterior column of the spinal cord. From this the stimulus is con- 
ducted along the motor nerve to the appropriate muscle, where it 
reteases energy, the muscle contracts, and the act is performed, 
Modifications of this general procedure depend on the source of the. 
original stimulus, whether from an organ of special sense or from 
an internal organ, etc., and the part towards which the outgoing 
stimulus is determined. 
, The locality at which the outgoing stimulus receives its direction 
1s evidently in the cells of the cortex of the lateral and anterior 
part of the hemisphere. This iis evidently the seat of the will. 
I must here recall the familiar fact that multitudes of acts which- 
display distinct design are performed by animals without conscious- 
aos aoe any share in the process. There are reasons for ; 
believing, owever, that such acts could never have originated ina 
State of unconsciousness of the actor. I will not enter this subject 
! Abstract of a hilosophical Society of Wash- 
ington, May i. before the Phi mop ' 
