Ordinary is a type of Condition. Condition is related to Treatment. 
Direction is related to South. you are likely to find Slave in/at/on South. Slave is a different concept from Servant. Servant is related to Civil. 
Ordinary --IsA--> Condition <--RelatedTo--> Treatment 
Direction <--RelatedTo--> South <--AtLocation-- Slave <--DistinctFrom--> Servant <--RelatedTo--> Civil 