XVIU PBOCEEDINGS OF THE 



these reviews there is a general logical confusion which it is often 

 very difficult to get over ; this arises from that aptness of illustration 

 and figurative language which form one of the great charms of Mr. 

 Darwin's works. It seems to carry his supporters, and sometimes 

 perhaps the author himself, beyond strict logical bounds ; and on the 

 other hand, his opponents, feeling themselves led imconsciously into 

 conclusions which they believe to be unsound, but of which they do 

 not see the fallacy, are induced to mistrust the substantial arguments 

 adduced. An apt illustration has a great persuasive influence, but 

 it is no argument. The comparison of the origin of species with the 

 origin of language, so well worked out by Lyell, is an excellent ex- 

 position of fallacies in some of the arguments opposed to Darwin's 

 hypothesis, but it is no evidence in its favour ; the two series of 

 phenomena not being ejusdem genet-is, what is known in the one is 

 no guide to what is unknown in the other. So it is also with the 

 comparison of the divergence and development of varieties with that 

 of the branches of a tree, and many others that explain his views 

 to his audience but must not be considered as supporting them. 

 Again, the figurative terms ' Laws of Nature,' ' Struggle for Life,' 

 * Natural Selection,' * the good of the Species,' although well-devised 

 and indispensable implements of reasoning, yet require the greatest 

 caution in their use, from the great difficulty in keeping one's mind 

 constantly alive to the difference betAveen the real and figurative 

 meaning of the words, or between their partial and general appli- 

 cation. A social law is a command issued by, or the expressed 

 or implied will of, an individual or a community : as this is the 

 most familiar to us of all laws, it is exceedingly difficult, in 

 speaking of the laws of nature (which are but observed sequences of 

 phenomena), to separate in our mind these facts, which we can ob- 

 serve, from a presumed Will which we cannot investigate. Thus 

 J. S. Mill in his treatise on Logic, besides defining the expression 

 at the outset, finds it necessary, in order to guard against all confu- 

 sion, frequently to amplify it into " laws or observed uniformities 

 of Nature." The same personification of nature in " Natural Selec- 

 tion," or in explaining " the course of Nature," carries the mind 

 rather to the presumed course of action of an intelligent being than 

 to what it is particularly intended to convey — a generalization of 

 observed phenomena, — ^besides that in all personifications it is so 

 difficult entirely to discard aU idea of human motives of action. Still 

 more confusion and misunderstanding of Mr. Darwin's arguments 

 appear to me to have prevailed relating to the " Struggle for Life." 

 The direct signification of an active struggle between individuals or 



