To be clear, cogent, concise and consistent is to be logical. Reference has been made to a striking tendency on the part of writers and speakers to use words loosely. It is a noticeable fact that scholars generally aim to be profound rather than clear, philosophical rather than pointed.
In the use of text books more or less pedagogical these are the common complaints: “I don’t understand what he means” or “You have to read so much to get so little.” This condition gives to the topic of definition a prominence which cannot be overlooked by those who are seeking the truth; because the definition is the clearest, briefest and altogether the most satisfactory way of describing an idea. Likewise the habit of defining any doubtful term reduces to a minimum the possibility of misunderstanding.
The subject must appeal strongly to the instructor, as he, above all others, should make his work stand for clearness, pointedness and continuity.
2. THE PREDICABLES.
A predicable is a term which can be affirmed or predicated of any subject. In the proposition, “A man is a rational animal,” the term “rational animal” is a predicable,because it can be affirmed of the subject man.
To gain a clear knowledge of the definition it is quite necessary to understand the five predicables which we shall consider in the following order:
1. Genus.
2. Species.
3. Differentia (difference).
4. Property.