RESULTS AND LIMITS OF SCIENTIFIC METHOD. 445 



apply that name to the passage through each part of 

 space of similar average trains of atoms, the particular 

 successions of atoms being governed only by the theory 

 of probability, and the law of divergence from a mean 

 exhibited in the Arithmetical Triangle. Such a universe 

 would correspond partially to the Lucretian rain of 

 atoms, and to that nebular hypothesis out of which 

 Laplace proposed philosophically to explain the evolution 

 of the planetary system. 



According to another extreme supposition, the intense 

 heat energy of this nebulous mass might have been 

 mostly radiated away into the unknown regions of outer 

 space. The attraction of gravity would then have shown 

 itself between each two particles, and the energy of 

 motion thence arising would, by incessant conflicts, be 

 resolved into heat and dissipated. 



Inconceivable ages might be required for the com 

 pletion of this process, but the dissipation of energy thus 

 proceeding could end only in the production of a cold 

 and motionless stone-like universe. The relation of cause 

 and effect, as we see it manifested in life and growth, 

 would then degenerate into the constant existence of 

 every particle in a fixed position relative to every other 

 particle. Logical and geometrical resemblances would stiU 

 exist between atoms, and between groups of atoms crys 

 tallized in their appropriate forms for ever more. But 

 time, the great variable, would bring no variation, and 

 as to human hopes and troubles, they would have come to 

 eternal rest. 



Science is not really adequate to proving that such 

 is the inevitable fate of the universe, for we can seldom 

 trust our best established theories and most careful in 

 ferences far from their data. Nevertheless, the most 

 probable speculations which we can form as to the history, 

 especially of our own planetary system, is that it origi- 



