argument

1. What is an argument?,
An argument, says Quintilian, is a way for making good a proof, by which one thing is concluded from another, and what is doubtful is confirmed by what is not.
On what are all arguments founded?
On reason, morals, or the affections.
What is the object of arguments from reason?
To inform the judgment, or, instruct.
How are arguments from reason divided?
Into artificial and inartificial.
What are, artificial arguments from reason?
They are such as arise from the subject upon which the orator treats. (Getty, 2)