20 THE SCIENCE OF LOGIC. 



simple notion stand without further analysis for the present. The 

 other terms just mentioned have, however, each a wider and a nar 

 rower meaning. For, the thoughts that make-up our knowledge 

 about anything at least in so far as they involve inferences, which 

 latter are very often latent even in the simplest judgments by 

 which we interpret sense experience may be perfectly consistent 

 with one another and exclude all contradiction and incompati 

 bility with one another, and may nevertheless be all false, all 

 erroneous, all out of conformity with fact, all out of joint with 

 reality. 



This will be made very evident when we come to deal with mediate 

 reasoning. But any simple example will serve to show the possibility of such 

 processes of thought. If, for instance, we take erroneous initial measurements 

 in some problem in mensuration, we may work out our problem in strict ac 

 cordance with mathematical rules, make all our calculations and inferences 

 correctly, arrive at a result which will be in strict conformity with every step 

 in the process back to the initial data, but which will be nevertheless wrong, 

 i.e. untrue, because our starting point was wrong. 



Processes and products of this kind are said to be &quot; valid &quot; or 

 &quot; correct &quot; or &quot; accurate &quot; in the narrower sense of being consistent 

 with themselves throughout, although not in the wider sense of 

 being true. 



Now there are many logicians who would confine the scope of 

 logic to the securing of mere consistency in our thoughts, not to 

 the securing of their truth. Distinguishing between fat forms of 

 our thought and its content or matter, they would have logic deal 

 with these forms apart altogether from their relations to the things 

 thought about. 1 Kant, Hamilton, Mansel, and Thomson incline 

 to this view, describing logic as the science of the formal laws 

 of thought, i.e. of the laws which govern pure thought or thought 

 simply as such the laws which regulate the forms of our thinking 

 processes independently of their matter. And as it is almost ex 

 clusively in the domain of deductive reasoning that we can thus 

 clearly distinguish between the form and the matter of thought 

 and secure consistency irrespective of truth, these authors unduly 

 confine their attention to deductive reasoning, to the neglect of 

 induction. 



1 Some logicians Whately, for instance propose mere verbal consistency as the 

 sole aim of logic. They thus confound logic with grammar. Language is the ex 

 pression of thought, and it is with thought that logic primarily deals. 



