Belief is a type of Content. Idea is a type of Content. Concept is a type of Idea. Concept is related to Liberty. 
Diet is related to Restriction. Restriction is related to Limit. 
Belief --IsA--> Content <--IsA-- Idea <--IsA-- Concept <--RelatedTo--> Liberty 
Diet <--RelatedTo--> Restriction <--RelatedTo--> Limit 