UNIFORMITY OF NA TURE 1 1 7 



also P &quot; ? Undoubtedly, the principle of uniformity is involved 

 in the application of the syllogism to any actual sphere of reality. 

 The Dictum de omni informs us that &quot;Whatever can be predi 

 cated of a class can be predicated about any member of the 

 class &quot;. But in order to make the predication about any new 

 instance of a class in any actual sphere, we must (a) identify the 

 instance as a member of that class, and () assume that all the 

 members have a stable, uniform nature, which constantly demands 

 the same predicates.^ 



When dealing with the merely formal aspect of the syllogism, 

 we regarded the terms of the latter as expressing abstract con 

 cepts of possible class-essences, apart from the question of their 

 verification or realization in any actual sphere of reality. We 

 supposed each abstract thought-object to be fixed, stable, un 

 changing. We had not, therefore, to raise the question whether 

 there is really a corresponding uniformity, regularity, stability, in 

 the actual spheres within which we suppose these concepts to 

 apply. 



It is when we pass from the purely formal and hypothetical 

 processes of arranging and dividing abstract concepts logically 

 according to intension and extension, and then reasoning &quot; con 

 sistently &quot; from them, to the material and. categorical processes of 

 classifying things, of verifying our definitions of the latter, and 

 reasoning &quot; truly&quot; or &quot;demonstratively &quot; about them, that we feel 

 called upon to justify our belief in that real uniformity in things, 

 which is the objective ground and condition of our thinking, 

 judging, and reasoning rightly about them. 2 



Dr. Venn, in his Empirical Logic? asks the interesting ques 

 tion : How is it that an analysis of induction raises the question 

 as to the origin of our belief in the uniformity of nature, while 

 no corresponding difficulty is supposed to be felt in respect of 

 deduction ? He takes the example of a man bitten by a cobra. 



1 C/. JOSEPH, op. cit., p. 378 ; MELLONE, op. cit., p. 252 (referring to Ueberweg, 

 Logic, 101) : &quot; the worth of the syllogism as a form of knowledge depends on the 

 assumption that general laws of causation hold in nature, and may be known &quot;. 



2 &quot; Geometrical proofs rest on the intuition of spatial relations, and algebraic 

 on the intuition of quantitative relations. . . . In fact, our belief in the uniformity of 

 space, and in the uniform formation of the numerical series, stands to mathematical 

 reasoning as our belief in the uniformity of nature stands to inductive. Deny them, 

 and in either case no general proposition remains possible any longer. Nay more, 

 no demonstration remains possible even about a particular case.&quot; JOSEPH, Logic, 

 pp. 506, 507. 



3 p. 124. 



