rationale (n.)

• account
• clarification
• cracking
• decipherment
• decoding
• demonstration
• demythologization
• editing
• elucidation
• emendation
• enlightenment
• excuse
• exegesis
• exemplification
• explanation
• explication
• exposition
• expounding
• grounds
• illumination
• illustration
• justification
• light
• logic
• philosophy
• pretense
• pretext
• principle
• rationalization
• reason
• reasoning
• simplification
• solution
• theory