TEE FIRST AND THE LAST CATASTROPHE. 283 



important words. He says, "We have here evidence of a limit of a 

 state of things which could not have been produced by the previous 

 state of things according to the known laws of Nature." It is not 

 according to the known laws of Nature, it is according to the known 

 laws of conduction of heat, that Sir William Thompson is speaking ; 

 and that mistake illustrates the fallacy of concluding that, if we con- 

 sider the case of the whole universe, we should be able, suppose we 

 had paper and ink enough, to write down an equation which would 

 enable us to make out the history of the world forward, as far forward 

 as we liked to go, but if we attempted to calculate the history of the 

 world backward, we should come to a point where the equation would 

 begin to talk nonsense, we should come to a state of things which 

 could not have been produced from any previous state of things, by 

 any known natural laws. You will see at once that that is an entirely 

 different statement. The same doctrine has been used by Mr, Murphy, 

 in a very able book, " The Scientific Bases of Faith," to build upon 

 it an enormous superstructure. I think the restoration of the Irish 

 Church was one of the results of it, but this doctrine is founded, as 

 I think, upon a pure misconception. It is founded entirely upon for- 

 getfulness of the condition under which the remark was originally 

 made. All these physical writers, knowing what they were writing 

 about, simjDly drew such conclusions from the facts which were before 

 them as could be reasonably drawn. They say, "Here is a state of 

 things which could not have been produced by the circumstances we 

 are at present investigating." Then your speculator comes, he reads a 

 sentence and says, " Here is an opportunity for me to have my fling." 

 And he has his fling and makes a purely baseless theory about the 

 necessaiy origin of the present order of Nature at some definite point 

 of time which might be calculated. But, if we consider the matter, 

 we shall see that this is not in any way a consequence of the theory 

 of the deduction of heat. If we apply that to the case of the earth, 

 we find that at present there is a certain distribution of temperature 

 in the interior of it, there is a law according to which the temperature 

 increases as we go down, and no doubt if we made further investiga- 

 tions, we should find that if we went deeper an accurate law would 

 be found, according to which the temperature increases as we go 

 downward. 



Now, assuming this to be so, taking this as the basis of our prob- 

 lem, we might endeavor to find out what was the history of the earth 

 in past times, and when it began cooling down. That is exactly what 

 Sir William Thompson has done. When we attempt it, we find that 

 theiie is a definite point to which we can go, and at which our equa- 

 tion talks nonsense. But we do not conclude that at that point the 

 laws of Nature began to be what they are; that is the point where 

 the earth began to solidify ; that is a process which is not a process 

 of the deduction of heat, and so the thing cannot be given by the 



