The Material of Argumentation.

The Material of Argumentation. 
The
essentials of an argument are the conclusion -that the speaker or writer has reached in his thought, and the reasons for the conclusion.
The materials which may furnish reasons for a conclusion may be derived from :
1.	Narration. We may argue that a man accused of a crime is innocent, because such a crime would be inconsistent with his past life, the details of which we should give,— the method which Cicero uses in his Defence of Roscius. Or we may argue from precedent, and also use narration.
2.	Description. We may argue that Bacon's character would have made it impossible for him to write Shakspere's plays. Cicero uses this method in The Manilian Law where he argues that Pompey's character entitles him to the command of the army against Mithridates.
3. Exposition. We may establish a conclusion by using general principles for our material—"John is a mortal, for all men are mortal," or by the use of analogy and other kinds of expository material. (See §§ 182-183.) In his speech on Conciliation, Burke argues from general principles against the employ¬ment of force.