Classical Logic and Rhetoric

The study of logic allows us to slow down and think about how we think so we can understand the acts of the intellect (apprehension, judgment, and reasoning) and analyze the products they create (definitions, statements, and arguments). With Aristotle as our guide, we can identify the 10 categories or types of predicates that can be said about a substance.

The first act of the intellect, apprehension, allows us to form definitions for the things we observe.

The second act of the intellect, judgment, allows us to make statements—truth-claims—about the things we observe.

The third act of the intellect, discursive reasoning, allows us to arrange statements into arguments. Validity concerns the form or structure of the argument, not its content.

Soundness concerns the content or truth of the argument. The study of logic helps us form arguments that are both valid and sound, compelling and true.

Rhetoric is the art of persuasive communication. The study of rhetoric helps us see the available means to persuade someone else of the truths of our own logic in a particular case.

The first canon of rhetoric is invention, or the discovery of proofs, such as appeals to logos (reason), ethos (character), and pathos (emotions).

The second canon of rhetoric is arrangement, or the particular organization of arguments and appeals to make them serve the greatest effect with your audience.

The third canon of rhetoric is style, which includes the overall tone and sound of your argument, your diction, and your particular choices of words and phrases.

The first three canons of rhetoric apply to all persuasive arguments, whether written or spoken. The final two, memory and delivery, are exclusive to spoken rhetoric.