4 THE SCIENCE OF LOGIC 



are mistakes which writers on inductive logic since the time of 

 Mill have not successfully avoided. Nor is it difficult to one 

 looking back, to see why such mistakes were, humanly speaking, 

 almost unavoidable. 



At different epochs men engaged in the investigation of those 

 higher and deeper problems which lie along the confines of philo 

 sophy and the special sciences, have been very differently impressed 

 as to the relative values of these latter in advancing human know 

 ledge. At one time the attention of scholars is drawn more 

 exclusively to one group of sciences, and again to another group : 

 and the logic of each period will be found to reflect faithfully the 

 then prevailing attitude, by its fuller consideration of the methods 

 and data of the dominating group. 



Thus we see that, broadly speaking, the Middle Ages wit 

 nessed an exhaustive development of the logic of Deductive 

 Reasoning. This was because men were then more satisfied with 

 their principles of knowledge, and perhaps more religiously-minded ; 

 because they set greater store on a knowledge of man s nature 

 and destiny than on a knowledge of the external universe ; be 

 cause for progress in the former they relied on (deductive) reason 

 ing from great, broad, general principles and truths that were 

 universally accepted at the time some on the authority of God 

 as being revealed by Him, others as self-evident, others again as 

 sufficiently established partly by their intrinsic evidence and partly 

 by the common assent and authority of the learned of past ages. 



Then came the period of the Renaissance, a period of doubt 

 about hitherto received principles, of revolt against authority and 

 rejection of traditional views and methods. On the one hand, 

 the hitherto accepted teachings of philosophy and religion were 

 critically re-examined ; and this new analysis had finally the 

 effect of adding to the traditional logic an extensive discussion 

 on the possibility and grounds of human certitude, and on the 

 ultimate criteria or tests of truth (17). On the other hand, a 

 closer attention to the study of external nature led to a wonder 

 ful progress in the domain of the physical sciences. The cultiva 

 tion of this fertile field of research has been rewarded by rich and 

 useful discoveries ; the physical universe is being eagerly explored 

 and made to yield up its secrets ; and the general laws and con 

 ditions according to which its phenomena unroll themselves are 

 the keys by which its most hidden agencies are brought to light 

 and utilized by human enterprise. Hence the high degree of 



