236 THE REIGN OF LAW. 



an explanation in one sense, but not in another. 

 It gives the reason why likeness should be aimed 

 at, but not the cause or the means through which 

 it has been brought about. Sameness in the pur- 

 pose for which things are intended, is a reason why 

 those things should be made alike 5 but it is no 

 explanation of the process to which the common 

 aspect is due. It is an explanation of the " why;" 

 but it is no explanation of the "how." Purpose 

 is attained in Nature through the instrumentality 

 of means ; and community of aspect in created 

 things suggests the idea of some common process 

 in the creative work. Thus, the likeness which is 

 due to common parentage serves the most impor- 

 tant purposes ; but it is not the less the result of a 

 physical cause, out of which it arises by way of 

 natural consequence. The likeness of the Hum- 

 ming Birds to each other suggests this kind of 

 cause. It is true that the organs which it prin- 

 cipally affects are specially adapted for a special 

 habit of life. They are fitted to enable the bird 

 to feed on the nectar, and the insects which fre- 

 quent the nectar of flowers, or the leaves or bark 

 of trees. But there are flowers and insects in 



