can be acquired only through definitions. They also say: “Composite definitions apply only to species composed of genus and differentia, not to simple species.”

Elsewhere I have summarized logic and its content, and indicated some of the error and misguidance into which it has led many people. This is not the place to elaborate on that, but we shall mention several arguments here.

The first argument:

Their statement, “A conception that is not self-evident can be attained only through a definition,” is false, because a definition is a statement made by the person defining. Here, a definition means a statement indicating the essence of the thing defined. Knowledge acquired through a definition can therefore arise only after that definition.

If the person who formulated the definition came to know the thing defined without a definition, their claim that “It can be known only through a definition” is invalid. If he came to know it through another definition, the same reasoning applies to that definition as to the first. If this definer came to know it after the first definition, circularity necessarily follows; if it was deferred, an infinite regress necessarily follows.