CHAP. XXII.] CONSTITUTION OF THE INTELLECT. 407 



spheres or spheroids. We determine approximately the path 

 of a ray of light through the atmosphere, by a process in which 

 abstraction is made of all disturbing influences of temperature. 

 And such is the order of procedure in all the higher walks of 

 human knowledge. Now what is remarkable in connexion with 

 these processes of the intellect is the disposition, and the cor- 

 responding ability, to ascend from the imperfect representations 

 of sense and the diversities of individual experience, to the per- 

 ception of general, and it may be of immutable truths. Where- 

 ever this disposition and this ability unite, each series of con- 

 nected facts in nature may furnish the intimations of an order 

 more exact than that which it directly manifests. For it may 

 serve as ground and occasion for the exercise of those powers, 

 whose office it is to apprehend the general truths which are in- 

 deed exemplified, but never with perfect fidelity, in a world of 

 changeful phenomena. 



6. The truth that the ultimate laws of thought are mathe- 

 matical in their form, viewed in connexion with the fact of the 

 possibility of error, establishes a ground for some remarkable con- 

 clusions. If we directed our attention to the scientific truth 

 alone, we might be led to infer an almost exact parallelism be- 

 tween the intellectual operations and the movements of external 

 nature. Suppose any one conversant with physical science, but 

 unaccustomed to reflect upon the nature of his own faculties, to 

 have been informed, that it had been proved, that the laws of 

 those faculties were mathematical ; it is probable that after the 

 first feelings of incredulity had subsided, the impression would 

 arise, that the order of thought must, therefore^ be as neces- 

 sary as that of the material universe. *We know that in the 

 realm of natural science, the absolute connexion between the 

 initial and final elements of a problem, exhibited in the mathe- 

 matical form, fitly symbolizes that physical necessity which binds 

 together effect and cause, j The necessary sequence of states and 

 conditions in the inorganic world, and the necessary connexion 

 of premises and conclusion in the processes of exact demonstra- 

 tion thereto applied, seem to be co-ordinate. It may possibly be 

 a question, to which of the two series the primary application of 

 the term "necessary" is due; whether to the observed constancy of 



