144 OF LAWS IN GENEKAL. 



nexions between particular leaves and particular kinds of 

 wood. But the fact that sundry of the uniform relations 

 which chiefly make up the organic sciences, were very early 

 recognized, is due to the high degree of vividness and fre 

 quency with which they were presented to consciousness. 

 Though the connexion between the sounds characteristic of 

 a bird, and the possession of edible flesh, is extremely in 

 volved ; yet the two terms of the relation are conspicuous, 

 often recur in experience, and a knowledge of their con 

 nexion has a direct bearing on personal welfare. Meanwhile 

 innumerable relations of the same order, which are displayed 

 with even greater frequency by surrounding plants and 

 animals, remain for thousands of years unrecognised, if they 

 are unobtrusive or of no apparent moment. 



When, passing from this primitive stage to a more ad 

 vanced stage, we trace the discovery of those less familiar uni 

 formities which mainly constitute what is distinguished as 

 Science, we find the succession in which knowledge of them 

 is reached, to be still determined in the same manner. This 

 will become obvious on contemplating separately the in 

 fluence of each derivative condition. 



How relations that have immediate bearings on the 

 maintenance of life, are, other things equal, fixed in the 

 mind before those which have no immediate bearings, the 

 history of Science abundantly illustrates. The habits of 

 existing uncivilized races, who fix times by moons and barter 

 so many of one article for so many of another, show us that 

 conceptions of equality and number, which are the germs of 

 mathematical science, were developed under the immediate 

 pressure of personal wants ; and it can scarcely be doubted 

 that those laws of numerical relations which are embodied in 

 the rules of arithmetic, were first brought to light through 

 the practice of mercantile exchange. Similarly with geo 

 metry. The derivation of the word shows us that it ori- 



