1855.] On Mental Education. 469 



always true ; but, on the other hand, we frequently have to 

 ask what is the fact ? often fail in distinguishing it, often fail 

 in the very statement of it, and mostly overpass or come short 

 of its true recognition. 



If we are subject to mistake in the interpretation of our 

 mere sense impressions, we are much more liable to error 

 when we proceed to deduce from these impressions (as supplied 

 to us by our ordinary experience) the relation of cause and 

 effect ; and the accuracy of our judgment, consequently, is 

 more endangered. Then our dependence should be upon 

 carefully observed facts, and the laws of nature ; and I shall 

 proceed to a further illustration of the mental deficiency I 

 speak of, by a brief reference to one of these. 



The laws of nature^ as we understand them, are the foun- 

 dation of our knowledge in natural things. So much as we 

 know of them has been developed by the successive energies 

 of the highest intellects, exerted through many ages. After a 

 most rigid and scrutinizing examination upon principle and 

 trial, a definite expression has been given to them ; they have 

 become, as it were, our belief or trust. From day to day we 

 still examine and test our expressions of them. We have no 

 interest in their retention if erroneous ; on the contrary, the 

 greatest discovery a man could make would be to prove that 

 one of these accepted laws was erroneous, and his greatest 

 honour would be the discovery. Neither should there be any 

 desire to retain the former expression : for we know that the 

 new or the amended law would, be far more productive in results, 

 would greatly increase our intellectual acquisitions, and would 

 prove an abundant source of fresh delight to the mind. 



These laws are numerous, and are more or less comprehen- 

 sive. They are also precise ; for a law may present an apparent 

 exception, and yet not be less a law to us, when the exception 

 is included in the expression. Thus, that elevation of tem- 

 perature expands all bodies is a well-defined law, though there 

 be an exception in water for a limited temperature ; because 

 we are careful, whilst stating the law, to state the exception 

 and its limits. Pre-eminent among these laws, because of its 

 simplicity, its universality, and its undeviating truth, stands 

 that enunciated by Newton (commonly called the law of gra- 

 vitation] , that matter attracts matter with a force inversely as 



