62 THE LIMITATIONS OF SCIENCE 



particles by means of the electroscope. These smaller 

 portions of matter are called electrons or sub-atoms, 

 and for the time being we have rested here. But would 

 anyone say that new methods of analysis and new 

 apparatus of registration are an impossibility, and 

 that the electron will not in future be divided? On 

 the other side of the series the mote, dancing in the 

 sunbeam and disappearing when the light fails it, is an 

 indivisible atom to the unskilled man deprived of sensi- 

 tive apparatus. The fact is, the atom as an objective 

 unit of matter has no existence ; we name that portion 

 of matter an atom when we have reached a limit of 

 appreciation of matter by our most sensitive apparatus. 

 If these fundamental and irrational assumptions of 

 plenum and sub-atom be once granted, then a me- 

 chanical explanation of many of the phenomena of na- 

 ture follows logically. But this is also true if we 

 postulate that matter is composed of the four es- 

 sences, earth, air, fire, and water; and one has only to 

 recall the success of Descartes with his three elements. 

 The question is, are the postulates true? If we can- 

 not verify them by experiment, then science should 

 reject them. On this criterion the sub-atom is as 

 vulnerable as any other postulate. The conclusions, 

 deduced, may give a truly mechanical explanation ; for, 

 in spite of denying the existence of matter in the be- 

 ginning, the substitute electricity is at once endowed 

 with all the essential characteristics of the discarded 



