Kinds of Ideas

A. second class of conditions to be studied by the rhetorician are determined by the nature of the idea to be communicated. All our ideas may be distributed under two heads : (1) ideas of individual objects ; and (2) general notions.

All our ideas may be referred to one of these four classes. If then we discover the laws of these four . elementary forms of discourse, we shall cover the whole ground of the conditions of communication depending upon the nature of the idea. These four classes of ideas give rise to four different processes of communi• cation :

(1)	The parts of a simultan4ous whole are presented to the mind by Description.

(2)	The parts of a successive whole are presented to the mind by Narration.

(3)	A general notion is unfolded to the mind by Exposition.

(4)	A proposition is confirmed to the mind by Argumentation.