YIRCEOW OX THE TEACHING OF SCIENCE. 



79 



that man arose out of the dust of the earth than 

 that the devil made the American horse-bones. 

 Worse than this, quaternary man goes too. 

 " Quaternaryman," says Virchow, " is no longer a 

 problem, but a real doctrine." But how do you 

 know that the devil did not make the fossil men 

 and all the flint implements ? This also is quite 

 as likely as that a human body was ever formed 

 by the direct transformation of non-living matter. 



" Well, then," I hear my anxious friend say, 

 with a sigh of relief, " we need not believe even in 

 the antiquity of man, or the evolution of horses. 

 They are all doubtful together." My good soul, 

 no student of science wants you to believe any- 

 thing unless you understand the nature of the 

 evidence for it, and then only to the extent which 

 is warranted by the evidence. There is no occa- 

 sion for you to form an opinion about these ques- 

 tions. You need have no fear of being singular. 

 There is always the defense of the ensign, who 

 was asked if he had seen Punch : " Well, you 

 know, the fact is, I am not a reading man." But, 

 if you wish to form an opinion, there are many 

 excellent manuals in which you may learn the 

 nature of the evidence and the methods of rea- 

 soning on which such an opinion should be based. 

 If your opinion should 'be adverse to the views 

 held by other scientific students, you will do great 

 service by stating your objections. Do not sup- 

 pose for a moment that we want you to believe on 

 any other terms. 



But what we do hope, for your sake, is this : 

 that you will not allow any dishonest person to 

 persuade you to disbelieve strongly in the doc- 

 trine of evolution, because Virchow has admitted 

 that certain parts of it are not yet absolutely 

 proved. It is one thing to believe that a doctrine 

 is false, and quite another thing to admit a theo- 

 retical doubt about it. 



I say a theoretical doubt, because it is a doubt 

 founded on the necessary imperfection of all hu- 

 man knowledge, and not on any practical defect 

 of the evidence. For a doubt precisely similar 

 in kind, though rather greater in degree, attaches 

 to the statement that the Russians took Plevna 

 last year. The evidence for the truth of this 

 statement is, I admit, very strong, and I suppose 

 no sane man would be disposed to question it for 

 a moment. We have the testimony of all the 

 newspaper correspondents, the course of subse- 

 quent events, the special information of the Gov- 

 ernment, and literally a whole army of witnesses 

 besides. Still, the Russians may have been one 

 and all under a continuous hallucination, and be 

 even now in imminent danger from Osman Pasha. 



Or those rascally papers may have laid their heads 

 together to deceive the whole British nation, down 

 to this hour. Either of these suppositions is a 

 great deal more likely than that the devil made 

 the old horse-bones, or that clay was transformed 

 into a human body. To be sure, they contradict 

 our experience of the uniformities of human ac- 

 tion to such an extent that we cannot seriously 

 entertain them. But the uniformities of human 

 action are known with far less accuracy and com- 

 pleteness than the uniformities which characterize 

 the generation of living bodies. One man under 

 an hallucination is common enough ; one news- 

 paper wrong in its facts is well within our expe- 

 rience. So that we have something to go upon 

 in conceiving a wide-spread delusion. But a man 

 without any mother at all, a real son of the soil, 

 is a thing our experience gives us no help toward 

 conceiving. 



If you went to a man of the world with this 

 doubt about Plevna, urging upon him that news- 

 papers were often mistaken, and begging him to 

 consider it in buying stocks, he would either take 

 you for a lunatic and humor your fancy, or he 

 would say : " Don't be so silly ; I have no pa- 

 tience with you." But the student of science is 

 obliged to have a great deal of patience, and de- 

 sires to have more. 



It seems, then, that the difference between the 

 doctrines of the descent of horses and of the de- 

 scent of men is not that one is a known fact and 

 the other a conjecture, because each of them is 

 practically as certain as such a doctrine can be, 

 though subject to the theoretical doubt which at- 

 taches to all human knowledge. And yet there 

 certainly is a great difference between the highly- 

 abstract and general considerations which go to 

 establish the one, and the more concrete, but still 

 rather difficult, arguments which prove the other. 

 The evidence in the two cases appeals to two 

 different classes of minds. The inference from a 

 modern horse-bone to the horse whose bone it 

 was is a tolerably easy one, which can be brought 

 home to many minds. From a fossil bone to the 

 ancient animal is a more remote inference, which 

 was at first made with considerable difficulty ; 

 still any person of ordinary intelligence may 

 be expected to grasp it. Then the geological in- 

 ferences, from stratified rocks to the sea or river 

 which deposited them, from successive position to 

 successive age, and so on, may have their way 

 smoothed by concrete examples so as to carry 

 their due weight without much mental strain. 

 The biological inferences which connect the mod- 

 ern horse with his fossil representative, based 



