Chapter Summary

Chapter 6: Categorical Logic: Syllogisms

6.1 Introduces the concepts of standard form, mood, and figure as these relate to categorical syllogisms.

6.2 Explains how to construct Venn diagrams for categorical statements, as a means of visualizing their meaning.

6.3 Explains how to construct Venn diagrams for categorical syllogisms in order to determine whether they are valid.

6.4 Discusses the Modern Square of Opposition, and explains why modern logicians do not endorse the Traditional Square of Opposition.

6.5 Explains how to evaluate enthymemes (i.e., arguments that have unstated premises or conclusions).

6.6 Explains how to evaluate sorites (categorical syllogisms linked in a chain). Also shows how term-complements can be removed in order to make categorical arguments easier to evaluate.

6.7 Provides a set of rules for determining the validity of syllogisms.