OF THE LAWS OF THOUGHT. 165 



elusions," he says, " are we then led respecting the nature and extent 

 of the scholastic logic ? 1 think to the following : that it is not a 

 science, but a collection of scientific truths, too incomplete to form 

 a system of themselves, and not sufficiently fundamental to serve as 

 the foundation upon which a perfect system may rest." 



In order that it may be understood in what sense it is held that 

 the foundation of the scholastic logic is defective, we make two other 

 quotations. ** That which may be regarded as essential in the spirit 

 and procedure of the AristoteliaUj and of all cognate systems of 

 logic, is the attempted classification of the allowable forms of infer- 

 ence, and the distinct reference of those forms, collectively or indi- 

 vidually, to some general principle of an axiomatic nature, such as 

 the Dictum of Aristotle." Again: "Aristotle's Dictum de omni 

 et nullo is a self-evident principle, but it is not found among those 

 ultimate laws of the reasoning faculty to which all other laws, how- 

 ever plain and self-evident, admit of being traced, and from which 

 they may in strictest order of scientific evolution be deduced. For 

 though of every science the fundamental truths are usually the most 

 simple of apprehension, yet is not that simplicity the criterion by 

 which their title to be regarded as fundamental must be judged. 

 This must be sought for in the nature and extent of the structure 

 which they are capable of supporting. Taking this view, Leibnitz 

 appears to me to have judged correctly when he assigned to the 

 principle of contradiction a fundamental place in logic ; for we have 

 seen the consequences of that law of thought of which it is the 

 axiomatic expression." The sum of what is contained in these pas- 

 sages, in so far as they bear on the point before us, is, 1st, That the 

 foundation of the Aristotelian, and of all cognate systems of logic, is 

 some such canon as the Dictum ; 2ud, That that canon, and other 

 maxims of a like description, though self-evident, are not deep 

 enough to serve as a basis for a science of logic in which all the 

 forms of thought are to be exhibited ; and, 3rd, That the only prin- 

 ciple sufficiently fundamental to form the basis of a complete science 

 of logic is the principle of contradiction. Now what is the real 

 state of the case ? ^N othing is more certain than that the Dictum 

 was not considered by Aristotle as either the exclusive or the ulti- 

 mate foundation of his logical system. Not the exclusive foundation ; 

 for, as a matter of fact, many of the forms of thought embraced in 

 rihe Aristotelian logic receive no direct warrant from the Dictum, 



