CIRCUMSTANTIAL EVIDENCE. 179 



cessary relations, and its first principles are de/lniiions which ex- 

 clude all ambiguity of language and ideas, and lead infallibly from 

 step to step to conclusions the most remote from common apprehen- 

 sion. But the subjects which admit of mathematical certainty are 

 comparatively few. Innumerable truths, the knowledge of which 

 is indispensable to happiness, and even to existence, must be be- 

 lieved upon evidence of an inferior kind. The subjects of moral 

 evidence are facts and relations which may or may not exist, and as 

 to which our reasonings and conclusions may be erroneous and false. 

 In the case of abstract truth, absolute and infallible demonstration 

 is the result, to which moral certainty the highest assurance we 

 can have of moral truth, is obviously and necessarily inferior. 



Numerous attempts have been made to give mathematical form 

 and precision to moral reasoning, but to little purpose, except as 

 they shew the ingenuity of their authors ; and, without presump- 

 tion, they may be declared to be destitute of any useful and practi- 

 cable application. A learned author, whose high praise it is to 

 have " done more than any other writer to rouse the spirit of judi- 

 cial reform/* but whose merits have been obscured by his eccentri- 

 cities of thought as well as of style, has gravely demanded whether 

 Justice requires less precision than Chemistry. The truth is that 

 the precision required in the one case is of a nature of which the 

 other does not admit. It M^ould surely be absurd to require the 

 proof of a moral or historic fact by the same kind of reasoning as 

 that by which we establish that the three angles of every triangle 

 are exactly equal to two right angles ; or that, in certain of the co- 

 nic sections, the latus rectum is a third proportional to the major 

 and minor axes. 



Unlike the assent which is given to mathematical truth, belief 

 may be of various degrees, between the highest and lowest of which 

 there are innumerable shades of conviction, which the latency of 

 mental operations, and the imperfections of language, render it im- 

 possible to define or express. Nor is it material, in relation to 

 subjects of moral inquiry, that exact expression cannot be given to 

 the inferior degrees of belief. The doctrine of chances, and nice 

 calculations of probability, cannot be applied to human actions, 

 which are essentially unlike, and dependent upon peculiarities of 

 person and of circumstances, which render it impossible to compare 

 them with a numeral standard. 



It is true, that, in the common affairs of life, we are frequently 

 obliged from necessity and duty to act upon evidence which pro- 

 duces the lowest state of belief; and Locke very justly remarks. 



