In explaining this device Aristotle references his Rhetoric, Prior Analytics, and Topics as well as other of his books. While Aristotle did not favor using persuasion in an unethical fashion, it became necessary to explain the enthymeme in order to refute other less ethical enthymemes that were used by some sophists of the time. To understand the enthymeme or rhetorical syllogism one must first understand a syllogism. The Syllogism - Validity and Soundness
A normal syllogism has 2 premises and a conclusion. For example one could say the following: All Men are Mortal (premise)
Socrates is a Man (premise)
Therefore Socrates is a Mortal (conclusion)
This is a valid and sound syllogism. Validity refers to when the conclusion follows from the premises, and a sound argument is a valid argument plus the premises are true. In the enthymeme one line or more in the syllogism is implied, and therefore not explicitly stated. For example in the following truncated syllogism, the premise "Socrates is a Man" is implied, and still the premises and the conclusion are clear. All Men are Mortal (premise)
Therefore Socrates is Mortal (conclusion)
But the enthymeme is not simply based on syllogistic logic, although syllogistic logic is a very important part of it. The enthymeme also tugs at the emotions. Lastly it appeals to ones sense of what is right or wrong (e.g., ethics) How is a syllogism able to accomplish this? The Persuasive Nature of the Enthymeme
The enthymeme is a popular technique of demogogues. People are persuaded to accept as true false beliefs against their will. While such a thing may not seem possible, when one examines the enthymeme one can see why this is so. Central to the enthymeme is understanding logos, pathos, and ethos (e.g., logic, emotion and ethics). First...