DEFINITION AND PROVINCE OF LOGIC. 5 



Of the science, therefore, which exjjounds the operations of the hu- 

 man understanding in the pursuit of truth, one essential part is the 

 inquiry ;• What are the truths which arc the objects of intuition or 

 consciousness, and what arc those which we merely infer I lint this 

 inquiry has never been considered a portion of logic. Its place is in 

 another and a perfectly distinct department of science, which may be 

 called the higher or transcendental metaphysics. For such is the title 

 which has been given to that portion of mental philosophy which 

 attempts to determine what part of the furniture of the mind belongs 

 to it orighially, and what part is constructed by itself out of materials 

 furnished from without. To this science appertain the great and 

 much debated questions of the existence of matter ; of the existence 

 of spirit, and the distinction between it and matter; of the reality of 

 time and space, as things without the mind, and distinguishable from 

 the objects which are said to exist i/i them. For, in the present state 

 of the discussion on these topics, it is universally allowed that the 

 existence of matter or of spirit, of space or of time, is, in its nature, 

 unsusceptible of being proved ; and that whatever is known of them, 

 is known by immediate intuition. To the same science belong the 

 inquiries into the nature of Conception, Perception, Memory, and 

 Belief; all of which are operations of the understanding in the pursuit 

 of truth ; but with which, as phenomena of the mind, or with the pos- 

 sibility which may or may not exist of analyzing any of them into 

 simpler phenomena, the logician as such has no concern. To this 

 science must also be refeiTed the following, and all analogous ques- 

 tions : To what extent our intellectual faculties and our emotions are 

 innate — to what extent the result of association. "Wliether God, and 

 duty, are realities, the existence of which is manifest to us a 2>riori by 

 the constitution of our rational faculty ; or whether our ideas of them 

 are acquired notions, the origin of which we are able to trace and 

 explain ; and the reality of the objects themselves a question not of 

 consciousness or intuition, but of evidence and reasoning. 



The province of logic must be restricted to that portion of our knowl- 

 edge which consists of inferences from truths previously known; 

 whether those antecedent data be general propositions, or particular 

 observations and perceptions. Logic is not the science of Belief, but 

 the science of Proof, or Evidence. So far forth as belief professes to 

 be founded upon proof, the office of logic is to supply a test for ascer- 

 taining whether or not the bfilief is well grounded. With the claims 

 which any proposition has to belief on its own intrinsic evidence, 

 that is, without evidence in the proper sense of the word, logic has 

 nothing to do, 



§ 5. As the far greatest portion of our knowledge, whether of gen- 

 eral truths or of particular facts, is avowedly matter of inference, 

 nearly the whole, not only of science, but of human conduct, is amen- 

 able to the authority of logic. To draw inferences has been said to be 

 the great business of life. Every one has daily, hourly, and moment- 

 ary need of ascertaining facts which he has not directly observed ; not 

 from any general pur|iose of adding to his stock of knowledge, but 

 because the facts themselves are of importance to his interests or to his 

 occupations. The business of the magistrate, of the military com- 

 mander, of the navigator, of the physician, of the agriculturist, is merely 



