A positive term is one which signifies the possession of certain attributes; e. g., metal, man, teacher, happy, honest.
A negative term is one which signifies the absence of certain attributes; e. g., inorganic, unhappy, non-metallic.
Terms which have the prefix not, non, un, in, dis, etc., or the affix less, are usually considered negative. The fact that there are some exceptions to this must not be overlooked. For example, unloosed, invaluable, are positive terms.
In theory every positive term has its corresponding negative; as pure, impure; organic, inorganic; metal, non-metal; good, not-good.
In some instances the language does not supply the word with the negative prefix because no need of it has been felt. The only way to express the negative of such words as good, table, etc., is to prefix “not” or “non.”
10. CONTRADICTORY AND OPPOSITE TERMS.
(See [page 38]).
Positive terms with their negatives have contradictorymeanings and therefore are referred to as contradictory terms. For example, honest and not-honest, metallic and non-metallic, perfect and imperfect, are contradictory terms. Such terms are mutually destructive. When we assert the truth of one we also imply the falsity of the other. If, for example, we assert that Abraham Lincoln was honest, we carry with this assertion the implication that Lincoln was not not-honest, or that any statement to the effect that he was not honest is false.
Contradictory terms, when used in a sentence, illustrate the law of excluded middle, as in the statements: “John’s recitation is either perfect or imperfect.” “This teacher is either just or not-just.” There is no middle ground in such propositions.
When contradictory terms are used in classification the whole is divided into but two classes; e. g.:
| honest | not-honest |
| agreeable | not-agreeable |
| metallic | non-metallic |
| perfect | imperfect |
| pure | impure |
| organic | inorganic |