the Fundamental Problem of Nature, 17 



not only exquisite order and arrangement in the structure of 

 plants and animals, but a unity of plan pervading the whole. 

 We see, in endless complexity, beauty, and simplicity, the most 

 perfect adaptation of means to ends. The advocates of the 

 physical theory are at least bound to show how it is probable 

 that this exquisite arrangement and unity of plan could have 

 been produced by means of chemical and physical agencies. 



Let us briefly consider what really has to be explained and 

 accounted for. Take, say, the leaf of a tree. The leaf is not 

 moulded by some external agency into its particular shape, but 

 is built up molecule by molecule. The form and structure of 

 the leaf is the result of the arrangement and disposition of the 

 particles of which it is composed. The thing to be accounted 

 for is not what moves the molecules or particles in its formation, 

 but what guides, directs, or determines the motion of these par- 

 ticles. The leaf could not be formed did not each particle move 

 in the right direction and stop at the proper time and at the proper 

 place. Each molecule occupies its own special position in the 

 leaf; consequently no two molecules in moving to their posi- 

 tions can take the same path. What, then, determines the par- 

 ticular path for each molecule ? or rather, what determines the 

 motion of each molecule along its particular path ? The mere 

 motion of the molecules is produced by force ; but what directs 

 or determines this force to move each particle along its special 

 path ? But the mystery is deeper still. Not only are the 

 paths of the molecules different, but they must all be adjusted 

 in relation to one another; for it is to the proper adjustment of 

 the paths that the form of the leaf is due. In other w^ords, the 

 motion of each molecule must be determined according to the 

 objective idea of the leaf. 



But the whole tree is built up of molecules, as well as the leaf. 

 The molecules which form the branch must be differently deter- 

 mined from the molecules forming the leaves ; and each mole- 

 cule of the branch must take a path different from all the other 

 molecules of the branch ; but the motions of all the molecules 

 must be determined according to the objective idea of the branch. 

 What holds' true of one branch holds true of all the other 

 branches ; and what holds true of the branches holds equally 

 true of the trunk, and of the roots, and of the whole tree. 

 Each particle must be determined not only in relation to the 

 objective idea of the particular leaf or the particular branch to 

 which it belongs, but in relation to the objective idea of the 

 tree. In the formation of the tree each molecule must move 

 along its special path, but the paths must be so adjusted to one 

 another that a tree shall be the result. But this is not all ; the 

 molecules must move and adjust themselves in relation to the 

 Phil, Mag, S. 4. Vol, 44. No. 290. July 1872. C 



