2. LOGIC RELATED TO OTHER SUBJECTS.
What the mind is may in time be answered satisfactorily by philosophy; what the mind does is described by psychology; what the mind knows is treated by logic. Again: the mind as a whole furnishes the subjectmatter for psychology, whereas logic is concerned with the mind knowing, aesthetics with the mind feeling, and ethics with the mind willing. Ethics attempts to answer the question, “What is right?” aesthetics, “What is beautiful?” and logic, “What is true?”
Though both psychology and logic treat of the knowing aspect of the mind, yet the fields are not identical. The former deals with the process of the knowing mind as a whole, while the latter is concerned mainly with the product of the knowing mind when it thinks. To be specific: The mind knows when it becomes aware of anything, moreover, this condition of awareness appears in two ways: first, immediately or by intuition; second, after deliberation or by thinking. For example, one may know immediately or by intuition that the object in the hand is a lead pencil, but when requested to state the length of the pencil there is deliberation involving a comparison of the unknown length with a definite measure. It may now finally be asserted that the pencil is six inches long. When we know without hesitation the process involved is intuition, whereas when the knowledge comes after some sort of comparison the mental act is called thinking. It, therefore, becomes the business of psychology to deal with both intuition and thinking while logic devotes its attention to thinking only, and even in this field the work of logic is more or less indirect.The specific scope of logic is the product of thinking or thought.[1] What are theforms of thought? What are the laws of thought? Are the several thoughts true? These are the questions which logic is supposed to answer.
For the logician thought has two sources, his own mind and the mind of others. In the latter case thought becomes accessible through the medium of language. There is in consequence a close connection between logic, the science of thought, and grammar, the science of language. Because of this near relation logic is sometimes called the “grammar of thought.”
To study any science properly one must have thoughts and since logic is the science of all thought the subject may be regarded as the science of sciences.
3. LOGIC DEFINED.
“Logic is the science of thought.” This definition commonly given is too brief to be helpful. Should not a definition of any subject represent a working basis upon which one may build with some knowledge of what the structure is to be? The following, a little out of the ordinary, seems to supply this condition: Logic as a science makes known the laws and forms of thought and as an art suggests conditions which must be fulfilled to think rightly.
In justification of the latter definition it may be argued that it covers the topics usually treated by logicians. It is said that a science teaches us to know while an art teaches us to do. As a science logic teaches us to know certain laws which underlie right thinking. For example, the law of identity which makes possible all affirmative judgments, such as “Some men are wise,” “All metals areelements,” etc. Likewise as a science logic acquaints us with certain universal forms to which thought shapes itself, such as definitions, classifications, inductions, deductions. Further, logic lays down definite rules which lead to right thinking. To wit: Because it is true of a part of a class it should not be assumed that it is true of the whole of that class: or, in short, do not distribute an undistributed term.
A possible profit to the student may result from a study of certain authentic definitions herewith subjoined:
(1) “Logic is the science of the laws of thought.” Jevons.