To understand and to be able to validate an idea, one needs to know what other ideas it depends on — what, if anything, must be grasped before one can understand the idea; this is the issue of logical hierarchy. In this lesson, Leonard Peikoff discusses the importance of logical hierarchy and takes the audience through the homework assignment on understanding the logical structure of Objectivism given in Lesson 4 of this course.

Note: Peikoff has since revised his view of the hierarchical structure of Objectivism. His revisions and reasons for them can be heard in his 1987 course Objectivism: The State of the Art, available on ARI Campus. It is instructive to compare the later presentation with the one given here, particularly in light of the importance Peikoff gives to the issue of logical hierarchy.