224 THE RIDDLE OF THE UNIVERSE. 



convinced of the unity of nature than the kinetic 

 theory which prevails in physics to-day. A mis- 

 understanding may easily arise from the fact that Yogt 

 puts his process of condensation in explicit contradic- 

 tion with the general phenomenon of motion ; but it 

 must be remembered that he is speaking of vibratory 

 movement in the sense of the physicist. His hypo- 

 thetical " condensation " is just as much determined 

 by a movement of substance as is the hypothetical 

 " vibration "; only the kind of movement and the 

 relation of the moving elements are very different in 

 the two hypotheses. Moreover, it is not the whole 

 theory of vibration, but only an important section 

 of it, that is contradicted by the theory of con- 

 densation. 



Modern physics, for the most part, still firmly 

 adheres to the older theory of vibration, to the idea 

 of an actio in distans and the eternal vibration of 

 dead atoms in empty space ; it rejects the pyknotic 

 theory. Although Vogt's theory may be still far 

 from perfect, and his original speculations may be 

 marred by many errors, yet I think he has rendered 

 a very good service in eliminating the untenable prin- 

 ciples of the kinetic theory of substance. As to my 

 own opinion — and that of many other scientists — I 

 must lay down the following theses, which are involved 

 in Vogt's pyknotic theory, as indispensable for a truly 

 monistic view of substance, and one that covers the 

 whole field of organic and inorganic nature : — 



I. — The two fundamental forms of substance, pon- 

 derable matter and ether, are not dead, and only 

 moved by extrinsic force, but they are endowed with 

 sensation and will (though, naturally, of the lowest 

 grade) ; they experience an inclination for condensation, 



