Explain this rule in your own words. 2. A definition should not be circular. The word being defined should
not be used as part of the definition. The difficulty this rule seeks to
prevent is that circular definitions go nowhere. If a student defines logic
as “the study of logic,” he hasn’t really given the meaning at all.
This rule is not necessarily broken when part of a word is used
in its definition. The definition of polar bear as “a white bear that
inhabits the arctic regions” is not circular, even though the word
“bear” appears in both parts.

This rule generally excludes the use of synonyms. If synonyms are al-
lowed, then define the word by synonym, not by genus and difference.