538 LOGIC OF THE MORAL SCIENCES. 



are not the principles of human nature, but results of those principles 

 under the circumstances in which mankind have happened to be placed. 

 When the Psalmist "said in his wrath that all men are bars," he enun- 

 ciated what in some ages and countries is borne out by ample experi- 

 ence • but it is not a law of man's nature to lie ; though it is one of the 

 consequences of the laws of his nature, that the habit of lying is nearly 

 universal when certain external circumstances exist universally, espe- 

 cially circumstances productive of habitual distrust and fear. When 

 the character of the old is asserted to be cautious, and of the young 

 impetuous, this, again, is but an empirical law; for it is not because of 

 their youth that the young are impetuous, nor because of their age that 

 the old are cautious. It is because the old, during their- many years of 

 life, have generally had much experience of its various evils, and having 

 suffered or seen others suffer much from incautious exposure to them, 

 have acquired associations favorable to circumspection : while the 

 young, as well from the absence of similar experience as from the 

 greater strength of the inclinations which tempt them into danger, 

 expose themselves to it more readily. Here, then, is the explanation 

 of the empirical law ; here are the conditions which ultimately deter- 

 mine whether the law holds good or not. If an old man has not been 

 oftener than most young men in 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, fi-om 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 empir- 

 ical law — if it rests only upon observation — there is no safety in apply- 

 ing it far beyond the hmits of time, place, and circumstance, in which 

 the observations were made. 



The really scientific truths, then, are not these empirical laws, but 

 the causal law^s 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 obsei-vation, 

 only to approximate generalizations. 



§ 2. This however is not, so much as is sometimes supposed, a pe- 

 culiarity of the sciences called moral. It is only in the simplest 

 branches of science that empirical 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 natu- 

 ral 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 degi-ee of regularity and 

 uniformity might be expected to exist among the effects ; and such is 

 really the case : they have a fixed order, and return in cycles. But 

 propositions which should express, with absolute con-ectness, all the 

 successive positions of a planet until the cycle is completed, would be 

 of almost unmanageable complexity, and could be obtained from the- 

 ory alone. The generalizations which can be collected on the subject 



