Logical Analysis is the process by which we examine and unfold the meaning of Terms. A Term, you remember, is the verbal expression of a Concept. In such analysis we endeavor to unfold and discover the quality-aspect and the quantity-aspect of the content of the concept. We seek, thereby, to discover the particular general idea expressed; the number of particular individuals included therein; and the properties of the class or generalization. Analysis depends upon division and separation. Development in the process of Logical Analysis tends toward clearness, distinctness, and exactness in thought and expression. Logical Analysis has two aspects or phases, as follows: (1) Division, or the separation of a concept according to its extension, as for instance the analysis of a genus into its various species; and (2) Partition, or the separation of a concept into its component qualities, properties and attributes, as for instance, the analysis of the concept iron into its several qualities of color, weight, hardness, malleability, tenacity, utility, etc.
There are certain rules of Division which should be observed, the following being a simple statement of the same:
I. The division should be governed by a uniform principle. For instance it would be illogical to first divide men into Caucasians, Mongolians, etc., and then further sub-divide them into Christians, Pagans, etc., for the first division would be according to the principle of race, and the second according to the principle of religion. Observing the rule of the "uniform principle" we may divide men into races, and sub-races, and so on, without regard to religion; and we may likewise divide men according to their respective religions, and then into minor denominations and sects, without regard to race or nationality. The above rule is frequently violated by careless thinkers and speakers.
II. The division should be complete and exhaustive. For instance, the analysis of a genus should extend to every known species of it, upon the principle that the genus is merely the sum of its several species. A textbook illustration of a violation of this rule is given in the case of the concept actions, when divided into good-actions and bad-actions, but omitting the very important species of indifferent-actions. Carelessness in observance of this rule leads to fallacious reasoning and cloudy thinking.
III. The division should be in logical sequence. It is illogical to skip or pass over intermediate divisions, as for instance, when we divide animals into horses, trout and swallows, omitting the intermediate division into mammals, fish and birds. The more perfect the sequence, the clearer the analysis and the thought resulting therefrom.
IV. The division should be exclusive. That is, the various species divided from a genus, should be reciprocally exclusive—should exclude one another. Thus to divide mankind into male, men and women, would be illogical, because the class male includes men. The division should be either: "male and female;" or else: "men, women, boys, girls."
The exercise of Division along these lines, and according to these rules, will tend to improve one's powers of conception and analysis. Any class of objects—any general concept—may be used for practice. A trial will show you the great powers of unfoldment contained within this simple process. It tends to broaden and widen one's conception of almost any class of objects.
There are also several rules for Partition which should be observed, as follows:
I. The partition should be complete and exhaustive. That is, it should unfold the full meaning of the term or concept, so far as is concerned its several general qualities, properties and attributes. But this applies only to the qualities, properties and attributes which are common to the class or concept, and not to the minor qualities which belong solely to the various sub-divisions composing the class; nor to the accidental or individual qualities belonging to the separate individuals in any sub-class. The qualities should be essential and not accidental—general, not particular. A famous violation of this rule was had in the case of the ancient Platonic definition of "Man" as: "A two-legged animal without feathers," which Diogenes rendered absurd by offering a plucked chicken as a "man" according to the definition. Clearness in thought requires the recognition of the distinction between the general qualities and the individual, particular or accidental qualities. Red-hair is an accidental quality of a particular man and not a general quality of the class man.