186 ESSAY ON THK RATIONALK OF 



able from realities, but require not the hypothesis of supernatural 

 agency. 



Dreams have occasionally led to the discovery of murders, of which 

 the case of William Corder, who was convicted and executed in 

 1828 for the murder of Maria Martin, presents a curious instance. 

 A philosophical mind will discover no causation in the conjunc- 

 tion of events like these, nor anything more than sequence; the 

 dream being the involuntary, and therefore vivid, recurrence in 

 sleep of thoughts more or less transient, upon which the mind has 

 meditated when awake; just as darkness seems more black and ter- 

 rible after momentary light. 



I forbear to increase the number of these illustrations, the perti- 

 nency of which will, however, be admitted when we consider what 

 the mass of mankind still are, and the indispensable importance and 

 inappreciable value of a correct standard of probability and analo- 

 gical reasoning. Hence we infer the necessity of an enlarged and 

 accurate knowledge of Nature, and of the springs and principles of 

 human conduct ; and thus it is that all the branches of knowledge 

 are directly or remotely allied, and mutually receive and reflect 

 light. 



From what has been advanced it results that, in every investiga- 

 tion based upon circumstantial evidence, the process is, in the first 

 instance, analytical and analogical. Every combination of facts is 

 resolved into its constituent elements, and we reason upon them, se- 

 parately and in combination, from what is known to what is sought. 

 The groundwork of our reasoning is our confidence in the stability 

 of the order of nature and in the operation of moral causes, which 

 have a tendency to influence human conduct with a similar unifor- 

 mity.* 



The argument from analogy is founded on the observation of re- 

 semblances ; and, of consequence, the more numerous and close they 

 are the safer will be our conclusions. Every branch of knowledge 

 presents instructive examples of the extent to which this mode of 

 reasoning may be securely carried. From shapeless ruins whose 

 date, as the poet expresses it, ^' o'erawes tradition,'' the scientific ob- 

 server is enabled to construct a model of the original in its primitive 

 symmetry and magnificence. A profound knowledge of compara- 

 tive anatomy enabled the immortal Cuvier, from a single fossil 

 bone, to describe the structure and habits of many of the extinct 

 animals of the antediluvian world. "^ The formation of the tooth,' 



* Abercronibie, On the Intellevtual Powers^ p. 205. 



