ETHOLOGY. 513 



contact with danger and difficulty, he will be equally 

 incautious : if a youth has not stronger passions than 

 an old man, he probably will be as little enterprising. 

 The empirical law derives whatever truth it has, from 

 the causal laws of which it is a consequence. If we 

 know those laws, we know what are the limits to the 

 derivative law : while, if we have not yet accounted for 

 the empirical law if it rests only upon observation 

 there is no safety in applying it far beyond the limits 

 of time, place, and circumstance, in which the observa- 

 tions were made. 



The really scientific truths, then, are not these 

 empirical laws, but the causal laws which explain 

 them. The empirical laws of those phenomena which 

 depend on known, causes, and of which a general 

 theory can therefore be constructed, have, whatever 

 may be their value in practice, no other function in 

 science than that of verifying the conclusions of theory. 

 Still more must this be the case when most of the 

 empirical laws amount, even within the limits of 

 observation, only to approximate generalizations. 



$ 2 . This however is not, so much as is sometimes 

 supposed, a peculiarity of the sciences called moral. 

 It is only in the simplest branches of science that empi- 

 rical laws are ever exactly true ; and not always in 

 those. Astronomy, for example, is the simplest of all 

 the sciences which explain, in the concrete, the actual 

 course of natural events. The causes, or forces, on 

 which astronomical phenomena depend, are fewer in 

 number than those which determine any other of the 

 great phenomena of nature. Accordingly, as each 

 effect results from the conflict of but few causes, a great 

 degree of regularity and uniformity might be expected 

 to exist among the effects ; and such is really the case : 

 VOL. n. 2 L 



