IO4 KANTS UNIVERSAL NATURAL HISTORY 



bodies presents favourable conditions for their production. 

 Moreover, what has been said regarding the origin of the 

 Solar System may be applied equally well to the System 

 of Jupiter. The moons will all have the orbits of their 

 revolution directed to one side, and almost in one plane; 

 and this from the same causes that determine the 

 analogy in the great system. But why do these satellites 

 move in their common direction towards the side on which 

 the planets revolve rather than to any other side ? 

 Their revolutions are not produced at all by the orbital 

 movements of the planets. They merely recognize the 

 attraction of the planet as a cause of their movement, 

 and as regards this attraction all directions are indifferent; 

 a mere chance will decide for one out of all possible 

 directions in accordance with, which the falling move- 

 ment of the matter turns into orbits. In fact, the cir- 

 cular course of the planet does nothing to impress on 

 the matter out of which the moons are to be formed, 

 revolutions round it ; all the particles around the planet 

 move in the same motion with it round the sun, and are 

 therefore in relative rest towards it. The attraction of 

 the planet alone does everything. But the orbital move- 

 ment which has to arise from that attraction, seeing that 

 it is absolutely indifferent as regards all the directions, 

 needs only a small external determination to be turned 

 to the one side rather than the other; and this small 

 degree of divergence it obtains from the advancing of 

 the elementary particles which revolve at the same time 

 around the sun with it but with more velocity, and 

 which come into the sphere of the attraction of the 

 planet. For this compels the particles nearer the sun, 

 which are revolving with more rapid motion, to leave the 



