Index is etymologically related to Indicate. Indicate is related to Sign. Sign can be used for Identification. Identification is a type of Evidence. 
Conscious is a synonym of Aware. Think requires Aware. you would Think because Remember. Qualify is a type of Remember. 
Index --EtymologicallyRelatedTo--> Indicate <--RelatedTo--> Sign --UsedFor--> Identification --IsA--> Evidence 
Conscious <--Synonym--> Aware <--HasPrerequisite-- Think --MotivatedByGoal--> Remember <--IsA-- Qualify 