Four more Fallacies. 109 



Leibnitz and Linnaeus would require, who held the 

 principle that natura non facit saltum, " Nature is 

 continuous." It is also what St. Thomas Aquinas 

 and Aristotle require; for the scholastic principle 

 is, supremum infirm attingit infimum supremi, " The 

 extremes of different orders touch one another." 

 These philosophers did not sustain evolution in the 

 sense of Haeckel or Huxley; yet they can claim for 

 the genuine philosophy of evolution the argument 

 drawn from the series of horses, and return thanks 

 for it to Professors Huxley and Marsh. When 

 therefore, at this late date, a scientist claims the 

 argument for his new and latest theory, he is reason- 

 ing post hoc, ergo propter hoc, on account of evolution 

 because the discovery of the fossil forms happens 

 to date after the theory, and to fall in with it. 

 That was a post hoc, ergo propter hoc argument, which 

 Lord Bacon pleasantly records as used by the 

 house-fly; perched on a chariot wheel, which 

 was whirling along and raising clouds of dust, 

 the fly said complacently: "See what a dust I 

 raise!" — a sophism quite familiar to us nowadays. 

 Fourthly, not very different from this is the line 

 which Mr. Darwin follows when he fills his books 

 with descriptions and narratives of what nature 

 does. And, having described the facts, he assumes 

 that he has explained the cause; and in the light of 

 his theory he calls the description, " natural selec- 

 tion." There is no harm in calling your description 

 anything you like; just as Mr. Spencer is free to 



