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TRANSACTIONS OF SECTION A. 623 
Can we group them in laws which will enable us to predict future conditions and 
positions? ‘Ihe ancient question never answered, but never ceasing to press for 
an answer, 
Having faith in our descriptive method, let us use it to describe our real attitude 
on the question. Do we, or do we not, as a matter of fact, make any attempt to 
apply the physical method to describe and explain those motions of matter which 
on the psychical view we term voluntary ? 
Any commonplace example, and the more commonplace the more is it to 
the point, will at once tell us our practice, whatever may be our theory. For 
instance, a steamer is going across the Channel. We can give a fairly good physi- 
cal account of the motion of the steamer. We can describe how the energy stored 
in the coal passes out through the boiler into the machinery, and how it is ulti- 
mately absorbed by the sea. And the machinery once started, we can give an account 
of the actions and reactions between its various parts and the water, and if only 
the crew will not interfere, we can predict with some approach to correctness how 
the vessel will run. All these processes can be likened to processes already 
studied—perhaps on another scale—in our laboratories, and from the similarities 
prediction is possible. But now think of a passenger on board who has received 
an invitation to take the journey. It is simply a matter of fact that we make no 
attempt at a complete physical account and explanation of those actions which 
he takes to accomplish his purpose. We trace no lines of induction in the ether 
connecting him with his friends across the Channel, we seek no law of force under 
which he moves. In practice the strictest physicist abandons the physical view, 
and replaces it by the psychical. He admits the study of purpose as well as the 
study of motion. 
He has to admit that here his physical method of prediction fails. In physical 
observations one set of measurements may lead to the prediction of the results of 
another set of measurements. The equations expressing the laws imply different 
observations with some definite relation between their results, and if we know one 
set of observations and that definite relation we can predict the result of the other 
set. But if we take the psychical view of actions, we can only measure the actions. 
We have no independent means of studying and measuring the motions which pre- 
ceded the actions, we can only estimate their value by the consequent actions. If we 
formed equations, they would be mere identities with the same terms on either side. 
The consistent and persistent physicist, finding the door closed against him, 
finding that he has hardly a sphere of influence left to him in the psychical region, 
seeks to apply his methods in another way by assuming that if he knew all about 
the molecular positions and motions in the living matter, then the ordinary physical 
laws could be applied and the physical conditions at any future time could be pre- 
dicted. He would say, suppose, with regard to the Channel passenger, that it is 
absurd to begin with the most complicated mechanism, and seek to give a physical 
account of that. He would urge that we should take some lower form of life where 
the structure and motions are simpler, and apply the physical methods to that. 
Well, then, let us look for the physical explanation of any motion which we 
are entitled from its likeness to our own action to call a voluntary motion. Must 
we not own that even the very beginning of such explanation is as yet non-existent ? 
It appears to me that the assumption that our methods do apply, and that purely 
physical explanation will suffice to predict all motions and changes, voluntary and 
involuntary, is at present simply a gigantic extrapolation, which we should unhesi- 
tatingly reject if it were merely a case of ordinary physical investigation. The 
physicist when thus extending his range is ceasing to be a physicist, ceasing to be 
content with his descriptive methods in his intense desire to show that he is a 
physicist throughout. 
Of course we may describe the motions and changes of any type of matter after 
the event, andina purely physical manner. Andas Professor Ward has suggested, 
in a most important contribution to this subject which he has made in his recently 
published Gifford Lectures,' where ordinary physical explanations fail to give an 
} «Naturalism and Agnosticism,’ Zhe Gifford Lectures, 1896-98, vol. ii. p. 71. 
