4 2 4 SCIENCE PROGRESS 



Suppose this time that a large number of them are scattered 

 at hazard over the table. The stimulus may be represented 

 by a new ball which comes into the system, and transfers its 

 motion to one of the balls lying at rest. This ball takes up the 

 energy, and travels forward to collide with one or more other 

 balls, which continue in their turn to pass the motion along. 

 Ultimately the motion may be supposed to reach some distant 

 ball on the outskirts of the system, which ball will travel off in 

 a direction depending upon the impacts which have gone 

 before. 1 This final motion represents the ultimate effect pro- 

 duced by the original stimulus. 



Now, interpreting Driesch's example in the terms of this 

 analogy, we see that the case he cites is one in which the 

 stimulus, or new ball, enters the system from three different 

 directions ; yet the resultant motion of the final ball is the same 

 in each case. On the other hand, he names two cases in which 

 the new balls enter by closely similar paths, and yet the 

 resultant motion is widely dissimilar. This, as Driesch correctly 

 states, is the supposition of mechanism. But does he correctly 

 state that such an event is impossible, is inconceivable, and 

 that it furnishes a permanent refutation of the entire scientific 

 position ? What is the alternative which he suggests ? That 

 some particular ball in the middle of the system miraculously 

 acquires a motion which was not conferred upon it by any 

 impact or by any physical or material cause ; that this created 

 energy of motion causes the ball to move in a specific direction 

 and collide with another ball, which again passes on the motion, 

 etc. ; and that the direction of this self-created motion is such 

 that its ultimate effect, when combined with the ultimate effects 

 of the motion produced by the original stimulus, gives rise to 

 the required resultant effect. In short, the problem is this : 

 Data : Incoming balls (constituting the stimulus) may deliver 

 their motion into the group at any of two or three different 

 points, and this motion in each case has an identical exit from 

 the group. Mechanistic explanation : There is no theoretical 

 difficulty whatever in supposing that this occurrence is due to 

 the normal effects of the impacts under the ordinary laws of 



1 In actual practice, of course, the motion would be dissipated throughout the 

 system. To improve the analogy we must assume a number of cushions, by which 

 the direction of motion may be changed, and the energy remain concentrated in 

 one ball at a time. 



